Bronco Drilling Company, Inc. Announces Monthly Operating Results

OKLAHOMA CITY, May 09, 2008 (BUSINESS WIRE) ----Bronco Drilling Company, Inc. (Nasdaq/GM:BRNC) announced today operational results for the month ended and as of April 30, 2008.

Utilization for the Company's drilling fleet was 78% for the month of April compared to 74% for the previous month and 69% for the first quarter of 2008. The Company had an average of 45 marketed drilling rigs in April compared to 45 in the previous month and 45 for the first quarter of 2008. The average dayrate on operating drilling rigs as of April 30, 2008, was $16,563 compared to $16,657 as of March 31, 2008, and $17,101 for the first quarter of 2008.

Utilization for the Company's workover fleet was 76% for the month of April compared to 75% for the previous month and 77% for the first quarter of 2008. The Company had an average of 53 marketed workover rigs in April compared to 50 in the previous month and 48 for the first quarter of 2008.

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.

 Bronco
   Drilling Company, Inc. Rig Status Report as of April 30, 2008 Est. Duration (2) ----------------- Rig Rig Status No. Horsepower
   Type Basin (1) Contract Days Date ---- ---------- ------ ---------- ------ -------- ------ ---------- 1 2 400 hp M I 2 4 950
   hp M Piceance O Term 209 11/25/2008 3 5 650 hp M Anadarko O well to well 4 6 650 hp M Anadarko O Term 302 2/26/2009 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 246 1/1/2009 8 10 1000 hp E
   Anadarko O well to well 9 11 1000 hp E Woodford O Term 340 4/5/2009 10 12 1500 hp E Anadarko O well to well 11 14 1200 hp
   E Woodford O Term 72 7/11/2008 12 15 1200 hp E Cotton O well to Valley well 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 Anadarko O well to well 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 3 wells 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 180 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 E Cotton O well to Valley well 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 O Term 52 6/21/2008 Valley 28 51 850 hp M Anadarko O well to well 29 52 850 hp M Anadarko O well to
   well 30 53 850 hp M I 31 54 850 hp M Woodford O Term 385 5/20/2009 32 55 1000 hp M Anadarko O 3 wells 33 56 1100 hp M Anadarko
   O well to well 34 57 1100 hp M Woodford O Term 325 3/21/2009 35 58 800 hp M Cotton O well to Valley well 36 59 850 hp M I
   37 60 850 hp M Anadarko O well to well 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 Woodford O Term 106 8/14/2008 42 76 700 hp M I 43 77 1200 hp M Anadarko O 3 wells
   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. 

Important Information

On January 23, 2008, Bronco Drilling Company, Inc. entered into a merger agreement with Allis-Chalmers Energy Inc. ("Allis-Chalmers"), providing for the acquisition of Bronco by Allis-Chalmers. In connection with the proposed merger, Allis-Chalmers filed a registration statement on Form S-4 (Registration No. 333-149326) with the Securities and Exchange Commission (the "SEC") on February 20, 2008, and filed an amendment to such registration statement on Form S-4 with the SEC on March 27, 2008, which registration statement contains a joint proxy statement/prospectus of both companies. Allis-Chalmers and Bronco may file other relevant documents concerning the proposed merger, including any amendments to such registration statement. INVESTORS ARE URGED TO READ THE JOINT PROXY STATEMENT/PROSPECTUS AND ANY OTHER RELEVANT DOCUMENTS FILED WITH THE SEC, BECAUSE THEY CONTAIN IMPORTANT INFORMATION REGARDING THE MERGER. Investors and security holders may obtain a free copy of the joint proxy statement/prospectus 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 may be obtained free of charge from Bronco's website at www.broncodrill.com or by calling Bronco'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 before making any voting or investment decision with respect to the proposed merger.

Allis-Chalmers and Bronco 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 and their ownership of Bronco 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.

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

Cautionary Note Regarding Forward-Looking Statements

The information in this report 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.

SOURCE: Bronco Drilling Company, Inc.

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

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