SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* LIME ROCK PARTNERS V LP (Last) (First) (Middle) 274 RIVERSIDE AVENUE (Street) WESTPORT CT 06680 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 06/26/2009	3. Issuer Name and Ticker or Trading Symbol Allis Chalmers Energy Inc. [ ALY ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	19,889,044(1)	D(2)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
7% Convertible Perpetual Preferred Stock	(3)(4)	(3)(4)	Common Stock	14,202,146(1)	$2.5625	D(2)

1. Name and Address of Reporting Person* LIME ROCK PARTNERS V LP (Last) (First) (Middle) 274 RIVERSIDE AVENUE (Street) WESTPORT CT 06680 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* LRP GP V, Inc. (Last) (First) (Middle) 274 RIVERSIDE AVENUE (Street) WESTPORT CT 06680 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Lime Rock Partners GP V, L.P. (Last) (First) (Middle) 274 RIVERSIDE AVENUE (Street) WESTPORT CT 06680 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. These securities are owned by Lime Rock Partners V, L.P. ("Lime Rock"), which is a member of a "group" for purposes of Section 13(d) of the Exchange Act including Lime Rock Partners GP V, L.P. and LRP GP V, Inc. The joint filers jointly are filing this Form 3 and information regarding the joint filers other than Lime Rock Partners V, L.P. is set forth on Exhibit 99 to this Form 3. The reporting persons disclaim beneficial ownership of the reported securities except to the extent of their pecuniary interests therein, and this report shall not be deemed an admission that the reporting persons are beneficial owners of the reported securities for purposes of Section 16 or for any other purpose.

2. Lime Rock directly owns all securities reported on this Form 3, all the other joint filers' ownership form is indirect, through one or more subsidiaries.

3. The Convertible Perpetual Preferred Stock ("Preferred Stock") is convertible into common stock at any time, at the holder's election. However, pursuant to the certificate of designations establishing the Preferred Stock, until the earlier of June 26, 2012 or the expiration of the standstill provisions included in the Investment Agreement between Lime Rock and the issuer, dated May 20, 2009, the Preferred Stock may not be converted if, immediately after giving effect to such conversion, (Continued Footnote 4)

4. Lime Rock and its affiliates who are deemed to beneficially own the common stock or Preferred Stock beneficially owned (as defined by Rule 13d-3 or Rule 13d-5) by Lime Rock and any person with whom Lime Rock or any such affiliates would constitute a "group" within the meaning of Section 13(d) of the Exchange Act with respect to common stock or Preferred Stock would beneficially own a number of shares of the issuer's common stock exceeding 35% of the total number of the issuer's issued and outstanding shares of common stock. At any time on or after June 25, 2014, the issuer may at its option cause the Preferred Stock, in whole but not in part, to be automatically converted. The issuer may exercise this right only if the closing sale price of the issuer's common stock equals or exceeds 300% of the then prevailing conversion price for the 30 consecutive trading days prior to the issuer's issuance of a press release announcing the mandatory conversion.

Remarks:

Exhibit 99: Joint Filer Information

	Lime Rock Partners V L.P.	07/06/2009
	Lime Rock Partners GP V, L.P., its general partner	07/06/2009
	LRP GP V, Inc., its general partner	07/06/2009
	/s/ John T. Reynolds	07/06/2009
	** Signature of Reporting Person	Date
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