Fractured formations have been the bane of drillers since the early days of rotary drilling. High-pressure formations with multiple fractures can present complex and hazardous well control conditions.
Even so, extensive natural fracturing can be desirable because of the prolific production associated with fracture porosity. You don't want to simply plug hydrocarbon-bearing fractures.
In the past, drillers used a number of conventional methods to combat the problem of lost circulation, such as using LCM (lost circulation material) or "drilling blind" to subsequently set casing across the loss zone.
However, asRick Stone and George Medley point out in their article beginning on page 30, a number of today's developing oil fields resist the efforts of such conventional methods. This is particularly true in sour, high-pressure fractured carbonate reservoirs in places such as Kazakh-stan, South America, and other regions of the world.
To deal with this problem, they introduce for Offshore readers the concept of light annular mudcap drilling (LAMCD), which they have used to address some of the problems associated with the hazards and production losses encountered in fractured formations. They have found LAMCD to be a safe, cost-effective drilling technique that can prove fruitful when drilling through massively fractured formations.
Matterhorn field project
The Matterhorn field in the Gulf of Mexico presented a number of challenges for Total. Because of the nature of the stacked reserves lying in layers from 6,000 to 11,000 ft below sea level, the developers anticipated the need for workovers – hence the deci-sion for a dry tree design. Because of the limited extension of the reservoir structure and the fact it was possible to drill all dev-elopment wells from a single location, project leaders chose a modified version of Atlantia's SeaStar TLP design for both technical and commercial reasons. Development of Matterhorn employed a modified TLP design to exploit the field's stacked reserves, asGulf of Mexico Editor Jaime Kammerzell describes in her project overview beginning on page 26. For a complete graphic presentation of the Matterhorn project, see the wall-size pullout poster inserted between pages 48 and 49. (If a previous reader has already taken the poster, you can get a free copy by calling 713-621-9720. Ask for Betty Kight.)
Drilling sector still has a pulse
To paraphrase Mark Twain, rumors of the death of the offshore drilling industry are exaggerated. In fact, you can expect the industry to spend $189 billion over the next five years on offshore drilling, and a major portion of that will be in deepwater arenas. That conclusion, and a number of other developments that may surprise you, is part of the annual deepwater drilling rig survey presented byInternational Editor Judy Maksoud beginning on page 34. Her report is accompanied by yet another wall-size poster, which can be found between pages 16 and 17. (Again, if it's missing, call the number above.)
That's the tip of the iceberg for this month. Don't miss the other features, business reports, technical articles, and industry news in the columns and special sections.
Eldon Ball
