Use these links to rapidly review the document
TABLE OF CONTENTS
INDEX TO FINANCIAL STATEMENTS

Table of Contents

As filed with the Securities and Exchange Commission on June 13, 2011

Registration No. 333-174017

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

Amendment No. 1
to

FORM S-1
REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933

LRR Energy, L.P.
(Exact name of registrant as specified in its charter)

Heritage Plaza
1111 Bagby Street, Suite 4600
Houston, Texas 77002
(713) 292-9510
(Address, including zip code, and telephone number, including
area code, of registrant's principal executive offices)

Eric D. Mullins
LRE GP, LLC
Heritage Plaza
1111 Bagby Street
Suite 4600
Houston, Texas 77002
(713) 292-9510
(Name, address, including zip code, and telephone number, including area code, of agent for service)

            Approximate date of commencement of proposed sale to the public: As soon as practicable after this Registration Statement becomes effective.

            If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box. o

            If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. o

            If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. o

            If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. o

            Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of "large accelerated filer," "accelerated filer" and "smaller reporting company" in Rule 12b-2 of the Exchange Act.

            The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the Registration Statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

Table of Contents

The information in this preliminary prospectus is not complete and may be changed. These securities may not be sold until the registration statement filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell nor does it seek an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION DATED JUNE 13, 2011

PRELIMINARY PROSPECTUS

LRR Energy, L.P.
Common Units
Representing Limited Partner Interests

We are a Delaware limited partnership formed by affiliates of Lime Rock Resources to operate, acquire, exploit and develop producing oil and natural gas properties in North America with long-lived, predictable production profiles. This is the initial public offering of our common units. No public market currently exists for our common units. We expect the initial public offering price to be between $             and $             per common unit. We intend to apply to list our common units on the New York Stock Exchange under the symbol "LRE".

Investing in our common units involves risks. Please read "Risk Factors" beginning on page 23.

These risks include the following:

•

We may not have sufficient cash to pay the minimum quarterly distribution on our units following the establishment of cash reserves and payment of expenses, including payments to our general partner.

•

We would not have generated sufficient available cash on a pro forma basis to pay the minimum quarterly distribution on all of our units for the twelve months ended March 31, 2011.

•

Unless we replace the oil and natural gas reserves we produce, our revenues and production will decline, which would adversely affect our cash flow from operations and our ability to make distributions to our unitholders.

•

A decline in oil, natural gas or natural gas liquids, or NGLs, prices will cause a decline in our cash flow from operations, which could cause us to reduce our distributions or cease paying distributions altogether.

•

Our general partner and its affiliates will own a controlling interest in us and will have conflicts of interest with us, and owe limited fiduciary duties to us, which may permit them to favor their own interests to the detriment of our unitholders.

•

Lime Rock Resources, Lime Rock Partners and other affiliates of our general partner will not be limited in their ability to compete with us, which could cause conflicts of interest and limit our ability to acquire additional assets.

•

Neither we nor our general partner have any employees and we rely solely on Lime Rock Management and Lime Rock Resources Operating Company to manage our business. The management team of Lime Rock Resources, which includes the individuals who will manage us, and Lime Rock Resources Operating Company will also provide substantially similar services to Lime Rock Resources, and thus will not be solely focused on our business.

•

Our unitholders have limited voting rights and are not entitled to elect our general partner or its board of directors. Affiliates of Lime Rock Management control our general partner and thus will have the power to control our operations.

•

Even if our unitholders are dissatisfied, they cannot remove our general partner without its consent.

•

Units held by persons who our general partner determines are not eligible holders will be subject to redemption.

•

Our tax treatment depends on our status as a partnership for federal income tax purposes. If the IRS were to treat us as a corporation, then our cash available for distribution to our unitholders would be substantially reduced.

•

Our unitholders will be required to pay taxes on their share of our taxable income even if they do not receive any cash distributions from us.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

We have granted the underwriters a 30-day option to purchase up to an additional                          common units on the same terms and conditions as set forth above if the underwriters sell more than                          common units in this offering.

The underwriters expect to deliver the common units on or about                          , 2011.

Prospectus dated                            , 2011

Table of Contents

(AREA OF OPERATIONS)

TABLE OF CONTENTS

i

ii

iii

          You should rely only on the information contained in this prospectus. We have not, and the underwriters have not, authorized anyone to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. We are not, and the underwriters are not, making an offer to sell these securities in any jurisdiction where an offer or sale is not permitted. You should assume that the information appearing in this prospectus is accurate as of the date on the front cover of this prospectus only. Our business, financial condition, results of operations and prospects may have changed since that date.

          Through and including                          , 2011 (25 days after the commencement of this offering), all dealers that effect transactions in these securities, whether or not participating in this offering, may be required to deliver a prospectus. This delivery is in addition to a dealer's obligation to deliver a prospectus when acting as an underwriter and with respect to their unsold allotments or subscriptions.

          This prospectus contains forward-looking statements that are subject to a number of risks and uncertainties, many of which are beyond our control. Please read "Risk Factors" and "Forward-Looking Statements."

iv

Industry and Market Data

          The market data and certain other statistical information used throughout this prospectus are based on independent industry publications, government publications or other published independent sources. Some data is also based on our good faith estimates based on our knowledge and experience in the industry in which we operate. Although we believe the third-party sources are reliable and that the third-party information used in this prospectus or in our estimates is accurate and complete, we have not independently verified the information, nor have we ascertained the economic assumptions underlying such information.

v

Table of Contents

PROSPECTUS SUMMARY

          This summary highlights information contained elsewhere in this prospectus. You should read the entire prospectus carefully, including "Risk Factors," the audited historical and unaudited pro forma financial statements and the notes to those financial statements. Unless otherwise indicated, the information presented in this prospectus assumes that the underwriters do not exercise their option to purchase additional common units.

          References in this prospectus to "LRR Energy," "we," "our," "us" or like terms refer collectively to LRR Energy, L.P. and its operating subsidiary. References to "Fund I" or "our predecessor" refer collectively to Lime Rock Resources A, L.P. ("LRR A"), Lime Rock Resources B, L.P. ("LRR B") and Lime Rock Resources C, L.P. ("LRR C"), which will sell and contribute oil and natural gas properties and related net profits interests and operations to us in connection with this offering. References to "Fund II" refer collectively to Lime Rock Resources II-A, L.P. and Lime Rock Resources II-C, L.P. References to "Lime Rock Resources" refer collectively to Fund I and Fund II. Our pro forma estimated proved reserve information as of December 31, 2010 and March 31, 2011 is based on reports prepared by Miller and Lents, Ltd. and Netherland, Sewell & Associates, Inc., our independent reserve engineers. A summary of our pro forma estimated proved reserve information as of March 31, 2011 prepared by (i) Miller and Lents, Ltd. is included in this prospectus in Appendix C and (ii) Netherland, Sewell & Associates, Inc. is included in this prospectus in Appendix D. We have included a glossary of some of the oil and natural gas terms used in this prospectus in Appendix B.

LRR Energy, L.P.

          We are a Delaware limited partnership formed in April 2011 by affiliates of Lime Rock Resources to operate, acquire, exploit and develop producing oil and natural gas properties in North America with long-lived, predictable production profiles. Our properties are located in the Permian Basin region in West Texas and southeast New Mexico, the Mid-Continent region in Oklahoma and East Texas and the Gulf Coast region in Texas. As of March 31, 2011, our total estimated proved reserves were approximately 30.3 MMBoe, of which approximately 84% were proved developed reserves. Approximately 56% of our pro forma revenues for the three months ended March 31, 2011 were from oil and natural gas liquids, or NGLs, and approximately 37% of our total estimated proved reserves were oil and NGLs as measured by volume. As of March 31, 2011, we operated 93% of our proved reserves. Based on our pro forma average net production of 6,144 Boe/d for the three months ended March 31, 2011, our total estimated proved reserves as of March 31, 2011 had a reserve-to-production ratio of approximately 13.5 years.

          Our general partner, LRE GP, LLC, is controlled by Lime Rock Management LP, or Lime Rock Management, which was founded in 1998 and manages approximately $3.9 billion of private capital for investment in the energy industry through its investment funds, Lime Rock Resources and Lime Rock Partners. Following its sale and contribution of oil and natural gas properties and related net profits interests and operations to us in connection with this offering, which we refer to as the Partnership Properties, Lime Rock Resources will own total estimated proved reserves of 15.3 MMBoe as of March 31, 2011, of which approximately 79% are proved developed reserves, with pro forma average net production of approximately 3,804 Boe/d for the three months ended March 31, 2011. In addition, Lime Rock Resources has approximately $625 million of additional acquisition capacity that it expects to deploy over the next two years to purchase additional oil and natural gas properties that may be suitable for acquisition by us in the future.

          Lime Rock Resources has informed us that it intends, from time to time, to offer us the opportunity to purchase some of its mature, producing oil and natural gas assets and to participate in potential joint acquisition opportunities. However, neither Lime Rock Resources nor any of its affiliates is obligated to offer or sell any of their properties to us or share future joint acquisition opportunities with us following the consummation of this offering.

1

Table of Contents

Our Properties

          Our properties consist of mature, low-risk onshore oil and natural gas reservoirs with long-lived, predictable production profiles located across three diverse producing regions: (i) the Permian Basin region in West Texas and southeast New Mexico, (ii) the Mid-Continent region in Oklahoma and East Texas and (iii) the Gulf Coast region in Texas.

          The following table summarizes pro forma information by producing region regarding our net proved reserves and producing wells as of March 31, 2011 and our average net production for the three months ended March 31, 2011.

          Based on our reserve reports as of March 31, 2011, the estimated decline rate for our existing proved developed producing reserves is approximately 12% per year for 2011 through 2015 and approximately 9% per year thereafter. As of March 31, 2011, our estimated proved developed non-producing reserves included 192 gross (158 net) recompletion, refracture stimulation and workover projects. In addition, as of March 31, 2011, our proved undeveloped reserves included 213 gross (140 net) identified drilling locations.

Our Hedging Strategy

          We plan to enter into hedging arrangements to reduce the impact of commodity price volatility on our cash flow from operations. Our strategy includes entering into commodity derivative contracts at times and on terms desired to maintain a portfolio of commodity derivative contracts covering approximately 65% to 85% of our estimated production from total proved developed producing reserves over a three-to-five year period at a given point of time, although we may from time to time hedge more or less than this approximate range. Lime Rock Resources will contribute to us at the closing of this offering commodity derivative contracts covering approximately 85% of our estimated production for each of the years ending December 31, 2011 through 2015 from total proved developed producing reserves as of March 31, 2011 based on our reserve reports. We expect that these commodity derivative contracts may consist of natural gas, oil and NGL financial swaps and collar contracts and natural gas basis financial swaps. By removing a significant portion of price volatility associated with production, we believe we will mitigate, but not eliminate, the potential effects of changing commodity prices on our cash flow from operations for those periods. For a description of our commodity derivative contracts,

2

Table of Contents

please read "Management's Discussion and Analysis of Financial Condition and Results of Operations — Pro Forma Liquidity and Capital Resources — Partnership Commodity Derivative Contracts."

Our Business Strategies

          Our primary business objective is to generate stable cash flows to allow us to make quarterly cash distributions to our unitholders and, over time, to increase our quarterly cash distributions. To achieve our objective, we intend to execute the following business strategies:

•

Exploit opportunities on our current properties and manage our operating costs and capital expenditures.



•

Pursue acquisitions of long-lived, low-risk producing oil and natural gas properties with reserve exploitation potential.



•

Leverage our relationship with Lime Rock Resources to provide additional acquisition opportunities through drop-down transactions and joint acquisitions.



•

Reduce the impact of commodity price volatility on our cash flows through an active hedging program.



•

Maintain a balanced capital structure to allow for borrowing capacity to execute our business strategies.

          For a more detailed description of our business strategies, please read "Business and Properties — Our Business Strategies."

Our Competitive Strengths

          We believe the following competitive strengths will enable us to achieve our business strategies:

•

Our diverse, predictable, long-lived reserve base with significant operational history under our control.



•

Our significant inventory of low-risk projects on existing properties that we operate.



•

Our relationship with Lime Rock Resources, which we expect will provide us with access to an inventory of additional mature oil and natural gas properties to acquire in drop-down transactions.



•

Our experienced acquisition and operations team with a proven ability to identify, acquire and exploit long-lived oil and natural gas assets.



•

Our balanced capital structure and financial flexibility.

          For a more detailed discussion of our competitive strengths, please read "Business and Properties — Our Competitive Strengths."

Our Principal Business Relationships

          Our general partner is controlled by Lime Rock Management. Lime Rock Management was founded in 1998 and manages approximately $3.9 billion of private capital for investment in the energy industry through its investment funds, Lime Rock Resources and Lime Rock Partners. Lime Rock Resources was formed by Lime Rock Management for the purpose of acquiring mature, low-risk producing oil and natural gas properties with long-lived production profiles, and currently consists of two investment funds, Fund I, formed in 2005, and Fund II, formed in 2008. Lime Rock Partners was formed by Lime Rock Management for the purpose of investing in energy companies worldwide in the exploration and production, energy service and oil service technology sectors of the oil and gas industry. Lime Rock Partners manages approximately $3.0 billion through five investment funds. Lime

3

Table of Contents

Rock Resources will be our largest unitholder following the consummation of this offering, owning an approximate         % limited partner interest in us.

          As a result of their significant ownership interests in us and our general partner, we believe Lime Rock Management and Lime Rock Resources will be motivated to support the successful execution of our business strategy and will provide us with opportunities to pursue acquisitions that will be accretive to our unitholders. Additionally, the management and operations team that manages and operates Lime Rock Resources will manage and operate our properties. Please read "Management" for more information about our officers and directors and their relationship with Lime Rock Management, Lime Rock Resources and Lime Rock Partners.

Risk Factors

          An investment in our common units involves risks. Below is a summary of certain key risk factors that you should consider in evaluating an investment in our common units. This list is not exhaustive. Please read the full discussion of these risks and other risks described under "Risk Factors."

Risks Related to Our Business

•

We may not have sufficient cash to pay the minimum quarterly distribution on our units following the establishment of cash reserves and payment of expenses, including payments to our general partner.



•

We would not have generated sufficient available cash on a pro forma basis to pay the minimum quarterly distribution on all of our units for the twelve months ended March 31, 2011.



•

Unless we replace the oil and natural gas reserves we produce, our revenues and production will decline, which would adversely affect our cash flow from operations and our ability to make distributions to our unitholders.



•

A decline in oil, natural gas or NGL prices will cause a decline in our cash flow from operations, which could cause us to reduce our distributions or cease paying distributions altogether.

Risks Inherent in an Investment in Us

•

Our general partner and its affiliates will own a controlling interest in us and will have conflicts of interest with us, and owe limited fiduciary duties to us, which may permit them to favor their own interests to the detriment of our unitholders.



•

Lime Rock Resources, Lime Rock Partners and other affiliates of our general partner will not be limited in their ability to compete with us, which could cause conflicts of interest and limit our ability to acquire additional assets.



•

Neither we nor our general partner have any employees and we rely solely on Lime Rock Management and Lime Rock Resources Operating Company, Inc., an affiliate of Lime Rock Resources that provides services to operate the oil and natural gas interests of Lime Rock Resources and that we refer to as Lime Rock Resources Operating Company, to manage our business. The management team of Lime Rock Resources, which includes the individuals who will manage us, and Lime Rock Resources Operating Company will also provide substantially similar services to Lime Rock Resources, and thus will not be solely focused on our business.



•

We have material weaknesses in our internal control over financial reporting. If one or more material weaknesses persist or if we fail to establish and maintain effective internal control over financial reporting, our ability to accurately report our financial results could be adversely affected.

4

Table of Contents

•

Our unitholders have limited voting rights and are not entitled to elect our general partner or its board of directors. Affiliates of Lime Rock Management that control our general partner will have the power to control our operations.



•

Our general partner may elect to cause us to issue common units to it in connection with a resetting of the target distribution levels related to our general partner's incentive distribution rights without approval of the conflicts committee of our general partner or unitholders. This may result in lower distributions to holders of our common units in certain situations.



•

Control of our general partner may be transferred to a third party without unitholder consent.



•

We may issue an unlimited number of additional units, including units that are senior to the common units, without unitholder approval, which would dilute unitholders' ownership interests.



•

Even if our unitholders are dissatisfied, they cannot remove our general partner without its consent.



•

Units held by persons who our general partner determines are not eligible holders will be subject to redemption.

Tax Risks to Unitholders

•

Our tax treatment depends on our status as a partnership for federal income tax purposes. If the IRS were to treat us as a corporation, then our cash available for distribution to our unitholders would be substantially reduced.



•

Our unitholders will be required to pay taxes on their share of our taxable income even if they do not receive any cash distributions from us.

Formation Transactions and Partnership Structure

          At the closing of this offering, the following transactions, which we refer to as the formation transactions, will occur:

•

We will enter into a purchase, sale, contribution, conveyance and assumption agreement with Fund I pursuant to which Fund I will sell and contribute to us (i) the Partnership Properties and (ii) certain commodity derivative contracts covering approximately 85% of our estimated production from total proved developed producing reserves for each of the years ending December 31, 2011 through 2015 based on production estimates in our reserve reports as of March 31, 2011;



•

We will assume approximately $27.3 million of LRR A's debt that currently burdens the Partnership Properties;



•

We will enter into a new $500 million credit facility under which we expect to borrow $145 million at the closing of this offering;



•

We will issue                          common units to the public, representing a         % limited partner interest in us;



•

We will issue to Fund I an aggregate of                          common units and                          subordinated units, representing an aggregate         % limited partner interest in us;



•

We will issue to our general partner                          general partner units, representing a 0.1% general partner interest in us, and all of our incentive distribution rights, which will entitle our general partner to increasing percentages of the cash we distribute in excess of $             per unit per quarter;

5

Table of Contents

•

We will make a cash distribution to Fund I of approximately $          million and we will repay in full the debt discussed in the second bullet above with funds from borrowings under our new credit facility, and we will pay to Fund I, in exchange for the Partnership Properties purchased from Fund I, approximately $          million consisting primarily of proceeds from this offering;



•

We will enter into a services agreement with Lime Rock Management and Lime Rock Resources Operating Company pursuant to which management, administrative and operational services will be provided to our general partner and us to manage and operate our business; and



•

We will enter into an omnibus agreement with Lime Rock Resources that will address certain indemnification matters.

          To the extent the underwriters exercise their option to purchase up to an additional                          common units, the number of common units issued to Fund I (as reflected in the fifth bullet above) will decrease by, and the number of common units issued to the public (as reflected in the fourth bullet above) will increase by, the aggregate number of common units purchased by the underwriters pursuant to such exercise. The net proceeds from any exercise of the underwriters' option to purchase additional common units will be used to pay additional cash consideration to Fund I for the Partnership Properties and to make an additional cash distribution to Fund I.

6

Table of Contents

Ownership and Organizational Structure of LRR Energy, L.P.

          The diagram below illustrates our ownership and organizational structure based on total units outstanding after giving effect to this offering and the related formation transactions and assumes that the underwriters do not exercise their option to purchase additional common units.

(1)

Lime Rock Management LP is ultimately controlled by its co-founders, Jonathan C. Farber and John T. Reynolds, who are Managing Directors of Lime Rock Partners. Mr. Farber is also a director of LRE GP, LLC. Our general partner's non-independent directors and certain of our general partner's executive officers have financial interests in Lime Rock Management LP and its general partner.

(2)

An entity controlled by Messrs. Farber and Reynolds controls each of the limited partnerships comprising Fund I. All of our executive officers and non-independent directors have financial interests in Fund I through ownership interests in its general partner entities.

(3)

Each of Fund I and Fund II owns a separate class of non-voting member interests (Class B and C, respectively) in our general partner that entitles it to receive, for a period of six years following the closing of this offering, 80% and 20%, respectively, of the distributions we make to our general partner on our incentive distribution rights.

7

Table of Contents

Principal Executive Offices and Internet Address

          Our principal executive offices are located at Heritage Plaza, 1111 Bagby Street, Suite 4600, Houston, Texas 77002, and our phone number is (713) 292-9510. Our website address is www.                           .com and will be activated in connection with the closing of this offering. We expect to make our periodic reports and other information filed with or furnished to the Securities and Exchange Commission, which we refer to as the SEC, available free of charge through our website as soon as reasonably practicable after those reports and other information are electronically filed with or furnished to the SEC. Information on our website or any other website is not incorporated by reference into, and does not constitute a part of, this prospectus.

Management of LRR Energy, L.P.

          Our general partner has sole responsibility for conducting our business and for managing our operations. Lime Rock Management is the controlling member of our general partner and will have the right to elect all of the members of the board of directors of our general partner, with at least three of these directors meeting the independence standards established by the New York Stock Exchange, or NYSE. At least one of our independent directors will be appointed prior to the date our common units are listed for trading on the NYSE. Lime Rock Management will appoint our second independent director within three months of the date our common units begin trading on the NYSE, and our third independent director within one year from such date. Our unitholders will not be entitled to elect our general partner or its officers and directors or otherwise directly participate in our management or operations. For more information about the executive officers and directors of our general partner, please read "Management — Directors and Executive Officers."

          Neither we, our general partner nor our operating subsidiary have any employees. Upon the closing of this offering, we will enter into a services agreement with Lime Rock Management and Lime Rock Resources Operating Company pursuant to which management, administrative and operational services will be provided to our general partner and us to manage and operate our business. For more information about the services agreement, please read "Management — Management of LRR Energy — Services Agreement."

          As is common with publicly traded partnerships and in order to maximize operational flexibility, we will conduct our operations through subsidiaries. We will initially have one subsidiary, LRE Operating, LLC, a Delaware limited liability company, that will conduct our operations.

Summary of Conflicts of Interest and Fiduciary Duties

General

          Our general partner has a legal duty to manage us in a manner beneficial to the holders of our common and subordinated units. This legal duty originates under state law in statutes and judicial decisions and is commonly referred to as a "fiduciary duty." However, the officers and directors of our general partner also have a fiduciary duty to manage the business of our general partner in a manner beneficial to its owners. Lime Rock Resources owns, holds and manages assets that are similar to ours and could compete with us. Lime Rock Partners' exploration and production portfolio companies also may own and manage assets that are similar to ours and could compete with us. In addition, certain of our general partner's executive officers and non-independent directors will continue to have economic interests, investments and other economic incentives in, as well as management and fiduciary duties to, Lime Rock Management and funds affiliated with Lime Rock Resources and Lime Rock Partners. As a result of these relationships, conflicts of interest may arise in the future between us and our unitholders, on the one hand, and our general partner and its owners and affiliates, on the other hand. For example,

8

Table of Contents

our general partner is entitled to make determinations that affect our ability to generate the cash flows necessary to make cash distributions to our unitholders, including determinations related to:

•

purchases and sales of oil and natural gas properties and other acquisitions and dispositions, including whether to pursue acquisitions that are also suitable for Lime Rock Resources;



•

the manner in which our business is operated;



•

the level of our borrowings;



•

the amount, nature and timing of our capital expenditures; and



•

the amount of cash reserves necessary or appropriate to satisfy our general, administrative and other expenses and debt service requirements and to otherwise provide for the proper conduct of our business.

          These determinations will have an effect on the amount of cash distributions we make to the holders of our units, which in turn has an effect on whether our general partner receives incentive cash distributions.

          For a more detailed description of the conflicts of interest and fiduciary duties of our general partner, please read "Risk Factors — Risks Inherent in an Investment in Us" and "Conflicts of Interest and Fiduciary Duties."

          Our partnership agreement may not be amended during the subordination period without the approval of our public common unitholders, other than in certain limited circumstances where no unitholder approval is required. However, after the subordination period has ended, our partnership agreement may be amended with the consent of our general partner and the approval of the holders of a majority of our outstanding common units (including common units held by Lime Rock Resources and its affiliates). Upon consummation of this offering, Lime Rock Resources will own an approximate          % limited partner interest in us (         % if the underwriters exercise their over-allotment option in full). Assuming that we do not issue any additional common units and Fund I does not transfer the common and subordinated units that it owns, Lime Rock Resources will have the ability to amend our partnership agreement, including our policy to distribute all of our available cash to our unitholders, without the approval of any other unitholder once the subordination period ends. Please see "Risk Factors — Risks Inherent in an Investment in Us" and "The Partnership Agreement — Amendment of the Partnership Agreement."

Partnership Agreement Modification of Fiduciary Duties

          Delaware law provides that Delaware limited partnerships may, in their partnership agreements, restrict or expand the fiduciary duties owed by the general partner to the limited partners and the partnership. Our partnership agreement limits the liability of our general partner and reduces the fiduciary duties it owes to holders of our common and subordinated units. Our partnership agreement also restricts the remedies available to holders of our common and subordinated units for actions that might otherwise constitute a breach of the fiduciary duties that our general partner owes to our unitholders. By purchasing a common unit, unitholders agree to be bound by the terms of our partnership agreement and, pursuant to the terms of our partnership agreement, are treated as having consented to various actions contemplated in our partnership agreement and to conflicts of interest that might otherwise be considered a breach of fiduciary or other duties under Delaware law. Please read "Conflicts of Interest and Fiduciary Duties — Fiduciary Duties" for a description of the fiduciary duties imposed on our general partner by Delaware law, the material modifications of these duties contained in our partnership agreement and certain legal rights and remedies available to our unitholders.

9

Table of Contents

The Offering

10

Table of Contents

11

Table of Contents

12

Table of Contents

13

Table of Contents

14

Table of Contents

15

Table of Contents

16

Table of Contents

Summary Historical and Pro Forma Financial Data

          We were formed in April 2011 and do not have historical financial operating results. Therefore, in this prospectus, we present the historical financial statements of our predecessor, which consists of the combined financial statements of LRR A, LRR B and LRR C. The following table presents summary historical combined financial data of our predecessor and summary pro forma financial data of LRR Energy as of the dates and for the periods indicated. The summary historical financial data as of December 31, 2009 and 2010 and for the years ended December 31, 2008, 2009 and 2010 are derived from the audited historical combined financial statements of our predecessor included elsewhere in this prospectus. The balance sheet data as of December 31, 2008 is derived from the audited combined historical financial statements of our predecessor not included in this prospectus. The summary historical financial data as of March 31, 2011 and for the three months ended March 31, 2010 and 2011 are derived from the unaudited historical combined financial statements of our predecessor included elsewhere in this prospectus.

          The summary unaudited pro forma financial data as of March 31, 2011 and for the three months ended March 31, 2011 and the year ended December 31, 2010 are derived from the unaudited pro forma condensed financial statements of LRR Energy included elsewhere in this prospectus. Our unaudited pro forma condensed financial statements give pro forma effect to the following:

•

the contribution and sale by Fund I to us of the Partnership Properties in exchange for an aggregate of              common units,             subordinated units and $          million in cash;



•

the issuance to our general partner of             general partner units, representing a 0.1% general partner interest in us, and the incentive distribution rights;



•

our assumption of approximately $27.3 million of LRR A's debt that currently burdens the Partnership Properties;



•

the issuance and sale by us to the public of             common units in this offering and the application of the net proceeds as described in "Use of Proceeds"; and



•

our borrowing of approximately $145 million under our new revolving credit facility and the application of the proceeds as described in "Use of Proceeds," including the repayment in full of the assumed debt discussed in the third bullet above.

          The unaudited pro forma balance sheet data assume the events listed above occurred as of March 31, 2011. The unaudited pro forma statement of operations data for the three months ended March 31, 2011 and the year ended December 31, 2010 assume the items listed above occurred as of January 1, 2010. We have not given pro forma effect to incremental selling, general and administrative expenses of approximately $2.5 million that we expect to incur annually as a result of being a publicly traded partnership.

          You should read the following table in conjunction with "— Formation Transactions and Partnership Structure," "Use of Proceeds," "Management's Discussion and Analysis of Financial Condition and Results of Operations," the historical combined financial statements of our predecessor and the unaudited pro forma condensed financial statements of LRR Energy and the notes thereto included elsewhere in this prospectus. Among other things, those historical combined financial statements and unaudited pro forma condensed financial statements include more detailed information regarding the basis of presentation for the following information.

          The following table presents a non-GAAP financial measure, Adjusted EBITDA, which we use in evaluating the financial performance and liquidity of our business. This measure is not calculated or presented in accordance with generally accepted accounting principles, or GAAP. We explain this measure below and reconcile it to the most directly comparable financial measures calculated and presented in accordance with GAAP.

17

Table of Contents

18

Table of Contents

Non-GAAP Financial Measures

          We include in this prospectus the non-GAAP financial measure Adjusted EBITDA and provide reconciliations of Adjusted EBITDA to net income and net cash provided by operating activities, our most directly comparable financial performance and liquidity measures calculated and presented in accordance with GAAP. We define Adjusted EBITDA as net income (loss):

•

Plus:



•

Income tax expense (benefit);



•

Interest expense-net, including realized and unrealized losses on interest rate derivative contracts;



•

Depletion and depreciation;



•

Accretion of asset retirement obligations;



•

Gain (loss) on settlement of asset retirement obligations;



•

Unrealized losses on commodity derivative contracts;



•

Impairment of oil and natural gas properties; and



•

Other non-recurring items that we deem appropriate.



•

Less:



•

Interest income;



•

Unrealized gains on commodity derivative contracts; and



•

Other non-recurring items that we deem appropriate.

          Adjusted EBITDA is used as a supplemental financial measure by our management and by external users of our financial statements, such as investors, commercial banks and others, to assess:

•

our operating performance as compared to that of other companies and partnerships in our industry, without regard to financing methods, capital structure or historical cost basis;



•

the ability of our assets to generate sufficient cash flow to make distributions to our unitholders; and



•

our ability to incur and service debt and fund capital expenditures.

          Adjusted EBITDA should not be considered an alternative to net income, operating income, cash flow from operating activities or any other measure of financial performance or liquidity presented in accordance with GAAP. Our Adjusted EBITDA may not be comparable to similarly titled measures of another company because all companies may not calculate Adjusted EBITDA in the same manner. The following table presents a reconciliation of Adjusted EBITDA to net income and net cash provided by operating activities, our most directly comparable GAAP financial performance and liquidity measures, for each of the periods indicated.

19

Table of Contents

Reconciliation of Adjusted EBITDA to Net Income