Exploring deeper

Victor Schmidt • Houston

A series of industry events that provides a snapshot of current conditions and attempts to project future directions made it abundantly clear there is increasing need for geologically directed exploration. Present seismic data is insufficient to use bright-spot amplitude anomalies for deep targets without the guidance of geological principles.

This observation is directed specifically to the deep shelf play in the Gulf of Mexico, but can be generalized to other world regions that will soon experience the same technology limits. It is especially true of exploration in deeper sediments where the limits of our present seismic technology are suspect. Readily available seismic surveys were shot with 4,000-6,000 m offsets and recorded for 8-10 sec. This is insufficient to confidently locate structures and exploration fairways at depths below 18,000 ft.

A new round of seismic shooting will be needed with 9,000-10,000 m offsets and recording lengths to 16 sec to see a basin's roots. Some shooting has already been done at these specs, and the data is impressive. Structures and reflectors are clearly seen down to 50,000 ft, well below the mother salt.

New surveys are on the industry's project list, but it will take some time before the new data will be widely available. In the interim, oil companies will need to use the intellect of their geoscientists wisely, rather than placing their trust in computer-driven amplitude extractions.

IODP begins

The Integrated Ocean Drilling Program began on Oct. 1. Contract awards by the National Science Foundation went to an alliance formed by the Joint Oceanographic Institutions, Texas A&M University, and the Lamont-Doherty Earth Observatory of Columbia University. The alliance will operate a scientific drillship allowing the United States to bring a research vessel online by next June as part of the IODP. The contract has an estimated cost of $626 million over 10 years.

The first expedition will take place next summer at the Juan de Fuca Ridge in the northeast Pacific Ocean to study fluids in the oceanic crust. IODP will use the Joides Resolution for this expedition. The Ocean Drilling Program used the vessel for nearly 20 years, and with minor improvements, IODP will use it for one to two years. The alliance will then acquire, convert, and operate an enhanced vessel capable of achieving the IODP's long-range science and engineering goals.

In addition to the Joides Resolution, IODP will use a riser vessel named Chikyu (Earth) under construction in Japan. Plans are also underway for additional countries to sponsor special platforms for drilling in shallow water and ice-covered regions.

Learning curve

When companies choose to explore deep sediments, they should remember that learning to deal effectively and efficiently with the drilling challenges of pressure and temperature in a deep trend will require drilling 12-20 wells per year to find the right combination of tools and technologies to "make hole" economically.

El Paso's President Ron Erskine shared his company's experience at the Back to the Shelf conference in Houston. By using a combination of rigs, bits, auto tracking, expandable casing, and new completion technologies, El Paso was able to save $5.5-14 million in drilling expenses as it gained experience in drilling deep, pressured wells.

Even more impressive from the exploration view is the way the company is extending its reach into deep sediments by applying its geological understanding of onshore trends. El Paso is using its geological expertise in the onshore Louisiana Miocene sand trend to track sedimentation patterns into deeper areas offshore in the Gulf of Mexico. The company has successfully used its geologists to locate new depocenters and older shelf edges that control sand deposition and hydrocarbon entrapment before drilling the deeper sediments offshore.

Focusing effort

Other trends gaining momentum are tighter integration between software tools and the application of historic data to traditional problems. At the Schlumberger Information Solutions Forum in Miami recently, Peter Goode, SIS president, outlined the "prize" hanging before information technology professionals:

• Increase oil industry production by 7%
• Reduce capex by 25%
• Increase drilling success by 200%.

These targets will be achieved through people and processes, connectivity and infrastructure, and software information technology, according to Goode.

Tighter integration will permit data to seamlessly flow between professional specialties increasing productivity. Real-time data will yield constant model/simulation updating that will identify and help avoid problem areas before they occur. Knowledge tools will quickly provide 90% solutions for routine wells based on historic drilling practice. This will allow the geoscientists to quickly test the drillability of a prospect and its economics, allowing the drilling engineer to focus on problem solving rather than routine well planning.

Valhall monitoring

BP Norge and partners Shell, Amerada Hess, and Total recently installed a permanent subsea seismic system over the Valhall field in the Norwegian sector of the North Sea. The OYO Geospace system contains 2,504 multi-component stations with 10,016 channels. Armored cables containing sensors and digitizing system were trenched to 1 m below mudline in 70 m water depth.

The 90 mi of cable are connected to the production platform where the data is gathered and temporarily stored. Data is then transmitted to shore by fiber optic cable for processing. The system also measures tidal action and reservoir subsidence at the rig site.

BP and Geospace Engineering Resources International, a division of OYO Geospace, collaborated on the project over two years. GERI designed the system, and OYO Geospace manufactured it in Houston.

TECHNOLOGY

Linux protection

Central Command announced the availability of Vexira Antivirus for Linux with real-time virus protection of the Samba, Netatalk, and NFS network shares. Vexira is a complete Linux antivirus defense system designed for easy and dependable virus prevention on Linux based servers. It uses multi-platform virus inspection technology to protect against more than 75,000 Windows, DOS, Linux, Macro, and Trojan horse applications in real-time using the open source Dazuko kernel module and Vexira Guard.

Research excellence

Citing Compagnie Generale de Geophysique's innovative use of technology in the field of seismic research, Dell designated the company as a Dell Center for Research Excellence. The company uses more than 3,000 Dell PowerEdge servers linked to form a high-performance computing cluster (HPCC).

CGG is the first corporate organization to receive this distinction from Dell and has the largest Dell-based HPCC deployment in its Houston offices. The company began the Houston cluster in 2001 with 128 servers and has expanded its capacity to more than 3,000 systems.

CGG uses HPCC throughout its global operations including: its Houston cluster, a 512-node cluster in Foxboro, England, and a smaller cluster in Canada. CGG has a worldwide compute capacity of over 30 tflops.