Depth imaging is becoming a hot ticket in spec offerings as seismic companies strive to differentiate their products from the pack.

As prestack depth migration and other depth imaging procedures become better understood and drop in price, seismic companies are beginning to offer them as add-ons to their basic spec packages. For instance, Diamond Geophysical plans to add some 3D prestack depth migration to its approximately 110-block 3D survey in the Gulf of Mexico's Garden Banks area covering the Llano discovery and the Macaroni field. Completed data also will include 3D.
Paradigm Geophysical has landed the first 3D prestack depth migration contract offshore Ireland from Enterprise Oil plc. Paradigm will install its Echos software suite and place some of its personnel at Enterprise's Dublin office.
Schlumberger is offering a 1,100sq km spec survey in the Gulf of Mexico's Alaminos Canyon area that includes regional evaluation of depth imaging (REDI). REDI is intended to reduce the risk for oil companies considering prestack depth migration projects by establishing the imaging potential at the earliest possible stage of lease block evaluation.
GX Technology has announced it will create a library of depth-imaged seismic data in the Gulf's DeSoto Canyon and Lloyd areas in partnership with TGS-Nopec. The joint venture is planned to help companies prepare for the 2001 Eastern Gulf lease sale. GX also has been selected by Anadarko as a major depth imaging partner, signing a contract last August to build a 3D velocity/depth model and perform 3D depth imaging over several hundred outer continental shelf blocks in the Gulf.
Why all the excitement? "While most of the seismic industry continues to experience slower than expected turnaround in oil company spending, over the past several months we have seen the opposite: a very strong upswing in demand for prestack depth imaging services," said GX President and Chief Operating Officer Mick Lambert. "Oil companies are accelerating their adoption of this key technology because it can significantly minimize drilling risk in most of today's important exploration trends."
Brazil
TGS-Nopec has consummated agreements with a subsidiary of Phillips Petroleum Co. and Chevron Overseas Petroleum Inc. to license the company's 2D non-exclusive seismic data. The Brasil '99 seismic survey is an 85,000km program being acquired jointly by TGS and Geco AS, a division of Schlumberger. Both oil companies plan to use the data to evaluate prospective acreage in future licensing rounds.
CGG is acquiring a 4,500sq km 3D seismic campaign in the Esperitu Santo area offshore Brazil. Data processing for the first phase will be done in Houston and will include prestack time migration. Processed data, including prestack time migration, will be available in May.
CGG also is acquiring a 4,500km 3D survey in the Campos Basin. Acquisition began in September, and processed data, including prestack time migration, will be available this month. The survey also includes 60,000km of high-density aeromagnetic data.
Western Geophysical has received authorization from Brazil's National Petroleum Agency to acquire 20,000km of non-exclusive 2D seismic data in the Santos Basin, the first of several multiclient projects the company is planning in Brazil. Conducted in 200 to 2,000m water depths, the Santos Basin survey is expected to tie existing wells within the basin. Western plans to include in the data package gravity and magnetic data as well as prestack and poststack time migration.
Western also has been awarded a contract to market about 46,000km of 2D seismic data covering virtually the entire coastline of Brazil. Commonly referred to as LEPLAC, this regional dataset, acquired and processed in the late 1980s and early 1990s, covers water depths from 50m to more than 4,000m.
Spectrum Energy is beginning a 50,000km 2D survey in the deepwater Campos Basin. The data will include well control.
PGS has announced it began acquisition on the first phase of a two-phase multiclient 3D survey within the Campos Basin. The first phase covers 8,500sq km of the Campos area. The Santos Basin survey will cover 5,000sq km.
Gulf of Mexico
Schlumberger and Seitel are participating in a two-part program to shoot four-component nonexclusive seismic. The alliance has designated about 444 offshore blocks in nine areas of the Gulf. The initial shoot will cover 35 offshore blocks in the West Cameron region and was scheduled to start in December. The second program, also targeting the Gulf area, is scheduled to begin during the second quarter of this year.
Veritas Marine Surveys began a 3D survey last summer over 115 OCS blocks in the East Breaks and Alaminos Canyon areas of the deepwater western Gulf. Data will be available some time this year.
CGG has entered a joint venture with TGS-Nopec and Geco-Prakla to acquire a 600-block 3D non-exclusive survey in the Mississippi Canyon area. The first 188 blocks were acquired last year, and acquisition will continue through the early part of this year. CGG will process the data in its Houston processing center.
TGS-Nopec began in October a 3D survey covering 2,789sq km in the Gulf's Mississippi Canyon.
Western Geophysical is continuing acquisition in its Eastern Gulf of Mexico survey, a 423-block program that began in July 1998.
Greenland
TGS-Nopec will arrange a field trip for representatives from exploration companies to tour the Nuussuaq Basin in July. The company recently finished acquisition on a 2,500km 2D survey in the area.
Portugal
TGP-Nopec has secured the right to acquire and sell seismic data on a multiclient or proprietary basis over the entire Portuguese shelf for a 5-year period.
China
Edcon Inc., Denver, Colo., is offering a package of more than 70,000km of marine gravity and magnetic data in the Pearl River Basin in the South China Sea. These data were acquired between 1980 and 1983 and are completely processed and leveled.
Vietnam
Fairfield Industries has won the exclusive rights to shoot a spec survey in the Mekong Delta region of Vietnam. The survey will comprise about 2,500km of 2D data onshore in the Mekong Delta, using dynamite as the energy source. Another 7,800km will be shot offshore using air guns. The offshore segment will run from the shoreline to about 25m of water depth. Acquisition began late last year.
Indonesia
TGS-Nopec has a 3,000km 2D program under way in the Misool Island region with Geco-Prakla, Migas and Pertamina to follow a 6,500km survey acquired in 1998. That survey tied key wells in the region and provided links to a variety of geological provinces.
Faeroese Continental Shelf
Western Geophysical and Geco-Prakla have conducted 2D surveys in this area. TGS-Nopec began a 5,000km 2D streamer survey in August. Processed data is available and includes reconnaissance AVO and gravity information.
Morocco
TGS-Nopec has signed an agreement with L'Office National de Recherches et d'Exploitations Petrolieres to acquire new geophysical data and reprocess older datasets from open acreage in the Atlantic and Mediterranean aquatories. The company was to begin acquisition of seismic and marine gravity data as well as aeromagnetic and oil seep data at the end of 1999.