ATP Updates Operations; Records 144% Production Increase During First Nine Months of 2006.

HOUSTON -- ATP Oil & Gas Corporation (NASDAQ: ATPG) today announced that the company placed six new wells on production during the first nine months of 2006 with an additional nine wells scheduled for first production between now and the middle of 2007. The new producing wells, particularly those at Mississippi Canyon 711 (Gomez) and Tors, have been the primary drivers for ATP's 144% increase in production during the first nine months of 2006 compared to the same period in 2005. New wells scheduled in the next nine months are projected to continue to increase production into 2007. In the first nine months of 2006, ATP paid USD 390.9 million for acquisition and development of oil and gas properties compared to USD 272.6 million during the same period in 2005. The company estimates that capital expenditures will be approximately USD 575 - USD 600 million for the full year 2006.

Gulf of Mexico Deepwater

Mississippi Canyon 711 (Gomez - 100% WI)

The third well at Gomez was completed during the third quarter 2006 in a new hydrocarbon bearing sand, which was not included as proved reserves in the company's December 31, 2005 reserve report and, in a proved undeveloped zone as well. Installation of a subsea flow line will follow later in the fourth quarter with first production expected in the first quarter 2007.

Drilling is scheduled to commence on a step out well in the first quarter 2007 and will target the sands at approximately 15,500 true vertical depths. If successful, this well is expected to be completed and on production in the second quarter 2007.

Since the first two wells were placed on production in March 2006, Gomez has enjoyed a higher than expected natural gas component of production. While the field was shut in 10 days during October for hurricane-related repairs to the Amberjack pipeline system, which ties into Mississippi Canyon 711, ATP was able to collect additional reservoir information in support of future field optimization. Production at Mississippi Canyon 711 is currently averaging 105 MMcfe/d net. In the first half 2007, the company plans to upgrade the natural gas compression and processing facilities on its floating production platform. The project is scheduled to be completed early in the third quarter 2007 and will increase facilities capacity 40% to 50% to approximately 200 MMcfe/d net.

Mississippi Canyon 941/942 and Atwater Valley 63 (Telemark Hub - 100% WI)

ATP acquired a 100% working interest in Mississippi Canyon 941/942 and Atwater Valley 63 in two separate private transactions in the second and third quarters of 2006. Previous drilling at each of these locations indicates to ATP the presence of recoverable hydrocarbons. Detailed engineering has begun for the development of the discoveries at each of these three blocks. The hull design of the floating production system will be a MinDOC system and will be fabricated in South Texas. The MinDOC, which was selected over competing technologies because of higher variable load capacity and lower cost, is scheduled for installation in 2008. Drilling will commence immediately after platform installation from a 2,000 hp platform rig. According to the company's estimates of recoverable hydrocarbons, the Telemark Hub represents ATP's largest property in the Gulf of Mexico.

Garden Banks 409 (Ladybug - 50% WI)

Ladybug was originally placed on production in September 2001 from two subsea wells. The original reservoirs produced until August 2006 at which time both wells were reentered for additional activities and production. The #1 well was recompleted into a 'behind' pipe proved reservoir in upper sands. The #3 well was side tracked (#3ST) to an exploratory up-dip target identified during Ladybug's first five years of production. The #3ST well encountered the targeted zone and was successfully drilled and tested. Both wells are expected to commence production this month.

Gulf of Mexico Shelf

West Cameron 663 (100% WI)

The WC 663 #1 well was brought online at the end of September after encountering a larger than expected proved undeveloped zone along with additional sands that were not included as proved reserves in ATP's December 31, 2005 reserve report.

Ship Shoal 351 (50% WI)

Ship Shoal 351 will be tied into ATP's operated Ship Shoal 358 platform and hub. The jacket and deck at Ship Shoal 351 have been installed and pipeline installation is in progress. A platform rig is set to begin a two-well program during December. Both wells should commence production in the first quarter 2007.

High Island 74 (40% WI)

The #2 exploratory well at High Island 74, north of ATP's producing well in the southern portion of the block, targeted a deeper sand at the 16,500' level. The #2 exploratory well found its intended target and was completed in the first quarter 2006. The platform has now been installed and the pipeline has been laid. Production is expected to commence this month.

South Marsh Island 233 (30% WI)

South Marsh Island 233 was part of a package acquired by ATP in late 2005. The #1 exploratory well was completed and tested during the third quarter. The well commenced production during October.

West Cameron 237 (75% WI)

West Cameron 237 was originally acquired as a producing property by ATP in 2001. In 2006, the #A-8 well was side tracked (the A-8 ST 1) to target a proved undeveloped zone. The #A-8 ST 1 was successfully drilled to a total depth at 7,600', encountered the targeted sand and commenced production in August.

South Timbalier 77 (75% WI)

This property was part of a package acquired by ATP in late 2005. South Timbalier 77 is an exploratory target with no reserves recorded by ATP. The #6 exploratory well is scheduled to commence drilling later this month. This medium risk, high potential well will target a zone at the 16,000' level.

North Sea

Tors - Kilmar & Garrow (85% WI)

In April 2006, ATP placed the first of several planned wells at Tors, the Kilmar K1, on production. The Kilmar K2 well was brought online during October 2006. The K2 well will slowly be brought up to capacity of approximately 30 MMcfe/d net as natural gas prices in the U.K. increase to an attractive level.

Drilling commenced on the Garrow G1 well immediately following the completion of the Kilmar K2 well. The G1 well is currently drilling at 3,000' and is targeting proved reserves at the 11,500' level. The G1 well, which should be completed and on production in the first quarter 2007, is expected to increase production at the Tors field to 60 MMcfe/d net.

Wenlock (100% WI)

The jacket and deck have been installed. Installation of the 27-kilometer pipeline is approximately 25% complete. The horizontal well, which will be drilled in the first quarter 2007 and will target a 150 meter column of Rotliegend sandstone, is expected to be on production in the second quarter 2007 at an average rate of 60 MMcfe/d net.

Helvellyn (50% WI)

Helvellyn will be brought back online in the fourth quarter 2006 following its planned summer shut in.

Production Update

Production for the third quarter averaged 174 MMcfe/d, exceeding previously announced guidance of 170 MMcfe/d. ATP is deliberately producing below its current net production capacity at approximately 200 MMcfe/d net in response to relatively low natural gas prices in the U.S. and the U.K. The natural gas price induced curtailments are primarily from several of ATP's Gulf of Mexico Shelf properties and Helvellyn and Tors wells in the North Sea. The wells will be restored to peak production as market conditions warrant. Based on the company's current production capacity, its voluntary production curtailments, the pipeline repairs noted above coupled with new wells scheduled to commence production during the fourth quarter 2006, production for the fourth quarter should average approximately 200 MMcfe/d net, an increase over the fourth quarter 2005 of 213%.

ATP expects to increase its production capacity above 300 MMcfe/d during 2007 following the natural gas compression and processing facilities upgrade at Mississippi Canyon 711 and as the following near-term wells are brought on production.

* Garden Banks 409 #1 well (4Q 2006)

* Garden Banks 409 #3 well (4Q 2006)

* High Island 74 #1 well (4Q 2006)

* Mississippi Canyon 711 #5 well (1Q 2007)

* Garrow G1 well (1Q 2007)

* Ship Shoal 351 #1 well (1Q 2007)

* Ship Shoal 351 #2 well (1Q 2007)

* Wenlock well (2Q 2007)

* Mississippi Canyon 711 #7 well (2Q 2007)

About ATP Oil & Gas

ATP Oil & Gas is an international offshore oil and gas development and production company with operations in the Gulf of Mexico and the North Sea. The company trades publicly as ATPG on the NASDAQ Global Select Market.

Forward-looking Statements 

Certain statements included in this news release are "forward-looking statements" under the Private Securities Litigation Reform Act of 1995. ATP cautions that assumptions, expectations, projections, intentions, or beliefs about future events may, and often do, vary from actual results and the differences can be material. Some of the key factors which could cause actual results to vary from those ATP expects include changes in natural gas and oil prices, the timing of planned capital expenditures, availability of acquisitions, uncertainties in estimating proved reserves and forecasting production results, operational factors affecting the commencement or maintenance of producing wells, the condition of the capital markets generally, as well as our ability to access them, and uncertainties regarding environmental regulations or litigation and other legal or regulatory developments affecting our business. The SEC has generally permitted oil and gas companies, in filings made with the SEC, to disclose only proved reserves that a company has demonstrated by actual production or conclusive formation tests to be economically and legally producible under existing economic and operating conditions. We and our independent third party reservoir engineers use the terms "probable" and "possible" and we use the term "recoverable hydrocarbons" to describe volumes of reserves potentially recoverable through additional drilling or recovery techniques that the SEC's guidelines may prohibit us from including in filings with the SEC. These estimates are by their nature more speculative than estimates of proved reserves. All estimates of probable and possible reserves in this news release have been prepared by our independent third party engineers and all estimates of recoverable hydrocarbons have been prepared by management. More information about the risks and uncertainties relating to ATP's forward-looking statements are found in our SEC filings.