SC 13G

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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934
(Amendment No. ___ )*

Basic Energy Services, Inc.

(Name of Issuer)

Common Stock, par value $0.01 per share

(Title of Class of Securities)

06985P100

(CUSIP Number)

December 31, 2005

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

     o Rule 13d-1(b)

     o Rule 13d-1(c)

     þ Rule 13d-1(d)

* The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.

CUSIP No. 06985P 10 0 

1	NAMES OF REPORTING PERSONS:
	First Reserve Corporation
	I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY):
	06-1210123
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS):
	(a)   o
	(b)   þ
3	SEC USE ONLY:
4	CITIZENSHIP OR PLACE OF ORGANIZATION:
	Delaware
		5	SOLE VOTING POWER:
NUMBER OF			0
SHARES		6	SHARED VOTING POWER:
BENEFICIALLY
OWNED BY			2,388,794
EACH		7	SOLE DISPOSITIVE POWER:
REPORTING
PERSON			0
WITH:		8	SHARED DISPOSITIVE POWER:
			2,388,794
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
	2,388,794
10	CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS):
	o
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9):
	7.1%*
12	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS):
	CO

*Based on the 33,785,359 shares of the Issuer's Common Stock that were issued and outstanding immediately following the completion of the Issuer's initial public offering, as reported in the Issuer's prospectus on Form 424B4 filed with the U.S. Securities and Exchange Commission on December 9, 2005.

CUSIP No. 06985P 10 0 

1	NAMES OF REPORTING PERSONS:
	First Reserve GP VIII, L.P.
	I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY):
	06-1507318
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS):
	(a)   o
	(b)   þ
3	SEC USE ONLY:
4	CITIZENSHIP OR PLACE OF ORGANIZATION:
	Delaware
		5	SOLE VOTING POWER:
NUMBER OF			0
SHARES		6	SHARED VOTING POWER:
BENEFICIALLY
OWNED BY			2,388,794
EACH		7	SOLE DISPOSITIVE POWER:
REPORTING
PERSON			0
WITH:		8	SHARED DISPOSITIVE POWER:
			2,388,794
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
	2,388,794
10	CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS):
	o
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9):
	7.1%*
12	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS):
	PN

*Based on the 33,785,359 shares of the Issuer's Common Stock that were issued and outstanding immediately following the completion of the Issuer's initial public offering, as reported in the Issuer's prospectus on Form 424B4 filed with the U.S. Securities and Exchange Commission on December 9, 2005.

CUSIP No. 06985P 10 0 

1	NAMES OF REPORTING PERSONS:
	First Reserve Fund VIII, L.P.
	I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY):
	06-1507364
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS):
	(a)   o
	(b)   þ
3	SEC USE ONLY:
4	CITIZENSHIP OR PLACE OF ORGANIZATION:
	Delaware
		5	SOLE VOTING POWER:
NUMBER OF			0
SHARES		6	SHARED VOTING POWER:
BENEFICIALLY
OWNED BY			2,388,794
EACH		7	SOLE DISPOSITIVE POWER:
REPORTING
PERSON			0
WITH:		8	SHARED DISPOSITIVE POWER:
			2,388,794
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
	2,388,794
10	CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS):
	o
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9):
	7.1%*
12	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS):
	PN

*Based on the 33,785,359 shares of the Issuer's Common Stock that were issued and outstanding immediately following the completion of the Issuer's initial public offering, as reported in the Issuer's prospectus on Form 424B4 filed with the U.S. Securities and Exchange Commission on December 9, 2005.

CUSIP No. 06985P 10 0

Item 1(a). Name of Issuer

Basic Energy Services, Inc.

Item 1(b). Address of Issuer’s Principal Executive Offices

400 West Illinois, Suite 800, Midland, Texas, 79701

Item 2(a). Name of Persons Filing

This Schedule 13G is filed on behalf of each of the following entities (collectively, the “Reporting Persons”):

          First Reserve Corporation

          First Reserve GP VIII, L.P.

          First Reserve Fund VIII, L.P.

Each of the shares listed in Item 4 below for each Reporting Person is directly held by First Reserve Fund VIII, L.P. (“Fund VIII”). First Reserve GP VIII, L.P. (“GP VIII”) is the general partner of Fund VIII and may be deemed to share beneficial ownership of the shares of the Issuer held by Fund VIII. First Reserve Corporation is the general partner of GP VIII and may be deemed to share beneficial ownership of the shares of the Issuer held by Fund VIII.

Item 2(b). Address of Principal Business Office of Each Reporting Person

One Lafayette Place, Third Floor, Greenwich, Connecticut 06830

Item 2(c). Citizenship of Each Reporting Person

Delaware

Item 2(d). Title of Class of Securities

Common Stock, par value $0.01 per share

Item 2(e). CUSIP Number

06985P 10 0

Item 3. If this statement is filed pursuant to §§240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:

(a)	o	Broker or dealer registered under Section 15 of the Act (15 U.S.C. 78o).
(b)	o	Bank as defined in Section 3(a)(6) of the Act (15 U.S.C. 78c).
(c)	o	Insurance company as defined in Section 3(a)(19) of the Act (15 U.S.C. 78c).
(d)	o	Investment company registered under Section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8).

CUSIP No. 06985P 10 0

(e)	o	An investment adviser in accordance with §240.13d-1(b)(1)(ii)(E).
(f)	o	An employee benefit plan or endowment fund in accordance with §240.13d-1(b)(1)(ii)(F).
(g)	o	A parent holding company or control person in accordance with §240.13d-1(b)(1)(ii)(G).
(h)	o	A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813).
(i)	o	A church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3).
(j)	o	Group, in accordance with §240.13d-1(b)(1)(ii)(J).

Item 4. Ownership

As of December 31, 2005, the following shares of Common Stock, par value $0.01 per share (the “Common Stock”), of Basic Energy Services, Inc., a Delaware corporation (the “Issuer”), were beneficially owned by the Reporting Persons (all percentages of Common Stock reported in this statement on Schedule 13G (the “Schedule 13G”) have been calculated based on the Common Stock outstanding immediately following the completion of the Issuer’s initial public offering, as reported in the Issuer’s prospectus on Form 424B4 filed with the U.S. Securities and Exchange Commission on December 9, 2005 (Registration No. 333-127517)).

First Reserve Corporation:	Amount beneficially owned:	2,388,794
	Percent of class:	7.1%
	Sole voting power:	0
	Shared voting power:	2,388,794
	Sole dispositive power:	0
	Shared dispositive power:	2,388,794
First Reserve GP VIII, L.P.	Amount beneficially owned:	2,388,794
	Percent of class:	7.1%
	Sole voting power:	0
	Shared voting power:	2,388,794
	Sole dispositive power:	0
	Shared dispositive power:	2,388,794
First Reserve Fund VIII, L.P.	Amount beneficially owned:	2,388,794
	Percent of class:	7.1%
	Sole voting power:	0
	Shared voting power:	2,388,794
	Sole dispositive power:	0
	Shared dispositive power:	2,388,794

Item 5. Ownership of Five Percent or Less of a Class

Not applicable.

2

CUSIP No. 06985P 10 0

Item 6. Ownership of More than Five Percent on Behalf of Another Person

Not applicable.

Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company

Not applicable.

Item 8. Identification and Classification of Members of the Group

Not applicable.

Item 9. Notice of Dissolution of Group

Not applicable.

Item 10. Certification

Not applicable.

3

SIGNATURE

After reasonable inquiry and to the best of its knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.

	FIRST RESERVE CORPORATION.
Date: February 9, 2006	By:	/s/ Anne E. Gold
		Name: Anne E. Gold
		Title:   General Counsel
	FIRST RESERVE GP VIII, L.P.
	By:	First Reserve Corporation
Date: February 9, 2006	By:	/s/ Anne E. Gold
		Name: Anne E. Gold
		Title:   General Counsel

	FIRST RESERVE FUND VIII, L.P.
	By:	First Reserve GP VIII, L.P.,
		Its General Partner
	By:	First Reserve Corporation,
		Its General Partner
Date: February 9, 2006	By:	/s/ Anne E. Gold
		Name: Anne E. Gold
		Title: General Counsel

4

EXHIBIT INDEX

Exhibit 1 Joint Filing Agreement dated February 9, 2006 among the Reporting Persons.

5

EX-99.1

EXHIBIT 1

JOINT FILING AGREEMENT

     We, the signatories of this statement on Schedule 13G filed with respect to the Common Stock of Basic Energy Services, Inc., to which this Agreement is attached, hereby agree that such statement is, and any amendments thereto filed by any of us will be, filed on behalf of each of us pursuant to and in accordance with the provisions of Rule 13d-1(k) of the Securities Exchange Act of 1934.

     Dated: February 9, 2006.

FIRST RESERVE FUND VIII, L.P.
By:	First Reserve GP VIII, LP, its General Partner,
	By:      First Reserve Corporation
	its General Partner
By:	/s/ Anne E. Gold
	Name:  Anne E. Gold
	Title:    General Counsel
FIRST RESERVE GP VIII, LP
By:	First Reserve Corporation, its General Partner
By:	/s/ Anne E. Gold
	Name:   Anne E. Gold
	Title:     General Counsel
FIRST RESERVE CORPORATION
By:	/s/ Anne E. Gold
	Name:   Anne E. Gold
	Title:     General Counsel