Allis Chalmers Energy 425 Business combination disclosure

Form 425

Filed by Bronco Drilling Company, Inc.
pursuant to Rule 425 under the Securities Act of 1933
and deemed filed pursuant to Rule 14a-12
of the Securities Exchange Act of 1934

Subject Company: Allis-Chalmers Energy, Inc.
Commission File No.: 001-02199

Bronco Drilling Company, Inc. Announces Monthly Operating Results

OKLAHOMA CITY, February 11, 2008 (BUSINESS WIRE)—Bronco Drilling Company, Inc., (Nasdaq/GM:BRNC), announced today operational results for the month ended and as of January 31, 2008.

Utilization for the Company’s drilling fleet was 64% for the month of January compared to 71% for the previous month and 76% for the third quarter of 2007. The Company had an average of 45 marketed rigs in January compared to 47 in the previous month and 53 for the third quarter of 2007. The average dayrate on operating rigs as of January 31, 2008, was $17,369 compared to $17,476 as of December 31, 2007, and $17,256 for the third quarter of 2007.

Utilization for the Company’s workover fleet was 82% for the month of January compared to 75% for the previous month and 78% for the third quarter of 2007. The Company had an average of 48 marketed workover rigs in January compared to 45 in the previous month and 35 for the third quarter of 2007.

The Company cautions that several factors other than those discussed above may impact the Company’s operating results and that a particular trend regarding the factors above may or may not be indicative of the Company’s current or future financial performance.

About Bronco Drilling

Bronco Drilling Company, Inc. is a publicly held company headquartered in Edmond, Oklahoma, and is a provider of contract land drilling and workover services to oil and natural gas exploration and production companies. Bronco’s common stock is quoted on The NASDAQ Global Market under the symbol “BRNC”. For more information about Bronco Drilling Company, Inc., visit http://www.broncodrill.com.

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Bronco Drilling Company, Inc.
Rig Status Report
as of January 31, 2008

								Est. Duration (2)
	Rig No.		Horsepower	Rig Type	Basin	Status (1)	Contract	Days		Date
1		2	400 hp	M		I
2		4	950 hp	M	Piceance	O	Term		299	11/25/2008
3		5	650 hp	M	Anadarko	O	well to well
4		6	650 hp	M	Anadarko	O	Term		26	2/26/2008
5		7	650 hp	M	Woodford	O	well to well
6		8	1000 hp	E	Williston	O	well to well
7		9	650 hp	M	Arkoma	O	Term		108	5/18/2008
8		10	1000 hp	E	Anadarko	O	well to well
9		11	1000 hp	E	Woodford	O	well to well
10		12	1500 hp	E	Anadarko	O	well to well
11		14	1200 hp	E	Woodford	O	Term		162	7/11/2008
12		15	1200 hp	E	Cotton Valley	O	Term		41	3/12/2008
13		16	1400 hp	E	Anadarko	O	well to well
14		17	1700 hp	E	Anadarko	O	well to well
15		20	1400 hp	E		I
16		21	2000 hp	E	Woodford	O	3 wells
17		22	1000 hp	E	Woodford	O	well to well
18		23	1000 hp	E	Piceance	O	Term		183	8/1/2008
19		25	1500 hp	E	Woodford	O	2 wells
20		26	1200 hp	E	Anadarko	O	3 wells
21		27	1500 hp	E	Piceance	O	Term		270	10/27/2008
22		28	1200 hp	E	Anadarko	O	3 wells
23		29	1500 hp	E	Woodford	O	3 wells
24		37	1000 hp	M		I
25		41	950 hp	M	Anadarko	O	well to well
26		42	650 hp	M	Anadarko	O	well to well
27		43	1000 hp	M	Cotton Valley	O	Term		142	6/21/2008
28		51	850 hp	M	Anadarko	O	well to well
29		52	850 hp	M		I
30		53	850 hp	M		I
31		54	850 hp	M	Woodford	O	Term		475	5/20/2009
32		55	1000 hp	M		I
33		56	1100 hp	M	Anadarko	O	well to well
34		57	1100 hp	M	Woodford	O	Term		415	3/21/2009
35		58	800 hp	M	Cotton Valley	O	Term		129	6/8/2008
36		59	850 hp	M		I
37		60	850 hp	M		I
38		62	1000 hp	M	Anadarko	O	well to well
39		70	450 hp	M	Anadarko	O	well to well
40		72	750 hp	M	Barnett	O	6 wells
41		75	750 hp	M		I
42		76	700 hp	M		I
43		77	1200 hp	M		I
44		78	1200 hp	M		I
45		97	850 hp	M	Anadarko	O	well to well

M -	Mechanical	I -	Idle
E -	Electric	O -	Operating

1	Rigs classified as “operating” are under contract while rigs described as “idle” are not under contract but are being actively marketed and generally ready for service.
2	The estimated contract duration is derived from discussions with our customer regarding their current projection of the days remaining to complete the project.
	Changes from the prior month are highlighted.

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Important Information

In connection with the proposed merger, Allis-Chalmers and Bronco Drilling will file a joint proxy statement/prospectus and both companies will file other relevant documents concerning the proposed merger transaction with the Securities and Exchange Commission (the “SEC”). INVESTORS ARE URGED TO READ THE JOINT PROXY STATEMENT/PROSPECTUS WHEN IT BECOMES AVAILABLE, AND ANY OTHER RELEVANT DOCUMENTS FILED WITH THE SEC, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION REGARDING THE MERGER. Investors and security holders may obtain a free copy of the joint proxy statement/prospectus (when available) and the other documents free of charge at the website maintained by the SEC at www.sec.gov.

The documents filed with the SEC by Allis-Chalmers may be obtained free of charge from Allis-Chalmers’ website at www.alchenergy.com or by calling Allis-Chalmers’ Investor Relations department at (713) 369-0550.

The documents filed with the SEC by Bronco Drilling may be obtained free of charge from Bronco Drilling’s website at www.broncodrill.com or by calling Bronco Drilling’s Investor Relations department at (405) 242-4444.

Investors and security holders are urged to read the joint proxy statement/prospectus and the other relevant materials when they become available before making any voting or investment decision with respect to the proposed merger.

Allis-Chalmers and Bronco Drilling and their respective directors and executive officers may be deemed to be participants in the solicitation of proxies from the respective stockholders of each company in connection with the merger. Information about the directors and executive officers of Allis-Chalmers and their ownership of Allis-Chalmers common stock is set forth in its proxy statement filed with the SEC on April 30, 2007. Information about the directors and executive officers of Bronco Drilling and their ownership of Bronco Drilling common stock is set forth in its proxy statement filed with the SEC on April 30, 2007. Investors may obtain additional information regarding the interests of such participants by reading the joint proxy statement/prospectus for the merger when it becomes available.

THIS PRESS RELEASE IS NOT AN OFFER TO SELL THE SECURITIES OF ALLIS-CHALMERS ENERGY, INC. AND IT IS NOT SOLICITING AN OFFER TO BUY THESE SECURITIES.

Cautionary Note Regarding Forward-Looking Statements

The information in this press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. These forward-looking statements include, but are not limited to, comments pertaining to estimated contract duration. Such statements are subject to risks, uncertainties and assumptions, including, but not limited to, early termination by the customer pursuant to the contract or otherwise, cancellation or completion of certain contracts or projects earlier than expected, operating hazards and other factors described in Bronco Drilling Company, Inc’s. Annual Report on Form 10-K filed with the SEC on March 8, 2007 and other filings with the SEC, which are available free of charge on the SEC’s website at www.sec.gov. Bronco cautions you that forward-looking statements are not guarantees of future performance and that actual results or developments may differ materially from those projected or implied in these statements.

Contact:	Bob Jarvis
	Investor Relations
	Bronco Drilling Company
	(405) 242-4444 EXT: 102
	bjarvis@broncodrill.com

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