What's new in exploration

	Vol. 224 No. 5
PERRY A. FISCHER, EDITOR

 Surface exploration methods have been around for decades. They usually suffer from the combined evils of poor perception, i.e., dogma, and lack of a proven theory to explain why a particular method would result in a hydrocarbon discovery.

 Both of these excuses are lame on even a casual inspection. Dogma, that necessary evil which slows progress through scientific culture, fear and habit, also protects us from the idiots and charlatans whose “black boxes” have a rich and colorful history. Dogma, in its most useful form, reminds us that skepticism is a virtue.

 There are theories as to why surface effects of hydrocarbon reservoirs should exist, and they are gaining credibility. Anomalous effects due to seepage, microseepage, radiation, magnetism and light absorption can be accurately detected and mapped by various methods. A theory on which a given geophysical method rests is both paramount and almost ignorable. 

 While a sound theory is highly desirable for furthering an exploration method, billions of barrels of oil have been discovered by applying empirical, analogous responses from similar, hydrocarbon-productive geology. However, move too far away, and the same geophysical response no longer works. A surface exploration study in next month’s issue uses just such methodology. Exploration methods often succeed by analogy.

 Just before writing this, I had a conversation with a geophysicist from a well-known oil company concerning these pathfinder methods. His comment was typical, “The problem with all of them is they cannot distinguish between commercial and non-commercial accumulations.”

 My response was, “And what method reliably can? Besides, their best use is in conjunction with conventional exploration methods, to reduce the amount of seismic that must be shot, and to reduce drilling risk. Given their generally modest cost, it’s surprising that they are not universally employed.” He did not reply.

 Published jointly by AAPG and SEG, and edited by Leonard LeSchack and Dietmar Schumacher, Surface Exploration Case Histories seeks to establish the utility of various surface exploration methods through examples. It is an extension of the successful AAPG Memoir 66. I’ve always been fascinated with the progress of exploration science; how odd that a 500-page book can be worth billions – and how few know it.

 Lease Sale 185. Although the awards are not final, Lease Sale 185 appears to have been a lackluster success, raising $315.5 million on 561 Central Gulf of Mexico blocks. One factor could be the nearly 60 Central Gulf leases that must be drilled or else relinquished during the next 19 months, which rises to over 1,400 leases in the next 5-1/2 years. The results do not seem to reflect persistently high oil and gas prices and, especially, the deep-gas shelf incentive of royalty relief. However, two-thirds of the leases occurred in less than 200-m waters – the cut-off depth for the deep-gas shelf incentives to apply.

 The highest bidder was Hunt Petroleum, offering $8.2 million for South Marsh Island Block 109 in 180-ft water. Hunt must know something no one else does, because the next highest bidder on the block was only $0.5 million. BP and ChevronTexaco concentrated on the ultra-deep water, where BP won 16 blocks and ChevronTexaco took 27 blocks.

 Noteworthy finds. ExxonMobil said that further exploratory drilling on Jansz field, 125 mi off the northwest coast of Western Australia, has confirmed a huge gas resource. Jansz-2 was drilled to delineate the Jansz-1 discovery made in 2000 in the WA-18-R exploration permit. Jansz-2 was drilled in 4,430 ft of water to about a 10,800-ft TD. Jansz field covers 766 sq mi and has an interpreted 1,300-ft gross gas column. Including an extension into the adjacent block, the field has an estimated 20 Tcf of recoverable gas. The company believes Jansz field to be the largest gas discovery ever in Australian waters. ExxonMobil holds a 50% interest and is operator, with ChevronTexaco holding the remaining interest. 

    Saudi Aramco discovered a new field in the eastern part of Saudi Arabia. Named Yebrin, the discovery is about 163 mi southeast of Riyadh, just south of the giant Ghawar field. The discovery well flowed 5,275 bpd of very light oil and 4.8 MMcfgd.

    A TotalFinaElf-led consortium made two oil discoveries in Angola’s offshore Block 17, making a total of 15 discoveries for the block. Acacia-1 was drilled in 3,380-ft-deep water and tested at a combined 13,712 bopd from two separate zones. The second well, Hortensia-1, is 6.3 mi north of Acacia in 2,725-ft-deep water and tested at 5,092 bopd. Both finds are located in the eastern section of Block 17, near the Perpetua discovery, made in 2000. This is the same prolific block that contains Girassol, which is now producing 200,000 bopd. 

    PDVSA said over the weekend that it made a discovery on the Chaguaramal field located in eastern Monagas state. The discovery contains light 32°-API crude. In situ estimates range to 460 MMbbl of oil and 1.6 Tcfg, with delineation drilling planned. 

    Anadarko made a gas discovery at its Jubilee prospect. Atwater Valley 349-1 is the first well drilled in the company’s Eastern Gulf of Mexico exploration program. The discovery was spudded in February in 8,800 ft of water, about 200 mi southeast of New Orleans. It encountered 83 ft of net pay and was drilled to the target depth of 18,310 ft. Estimated field size is 40 – 50 MMboe. Anadarko holds a 100% interest in Jubilee and adjacent blocks. 

 Pending legislation. The US House passed an energy bill as expected. It now goes to the Senate, where no doubt it will run into problems. However, Part 3 is likely to pass largely intact. It provides for programs to promote “ultra-deepwater and unconventional natural gas and other petroleum resources.” The program has three elements: ultra-deepwater technology, ultra-deepwater architecture, and unconventional gas and other resource exploration and production.

 Essentially, the legislation calls for the formation of non-profit committees and consortia comprising members from public and private institutions, laboratories and industry, chosen by the Secretary of the Interior. These consortia will conduct demonstration projects, technology development and transfer through awards in areas that include coal-bed methane, deep drilling, gas production from shales and tight sands, and other technologies. Patent rights would have to be worked out among consortia members.