When it comes to reaching reserves, it's obvious that directional companies have huge responsibilities to "get there."

What's less obvious is the value that independent directional companies generate for operators. Since being set up in 1977 in Lafayette, La., Tri-city Services Inc. has developed a reputation for objectivity and keeping things simple. This aids it in analyzing and recommending directional solutions. What has helped the company do this is a combination of treating each well's targets individually and thinking creatively about directional planning. The company has now planned and drilled more than 500 wells including several multi-well platforms.

Drilling engineer Greg Beazley said, "The overriding challenge is to maximize production while constructing as simple a well as possible. The next step is to rank solutions according to how effectively they meet well target needs. There is no incentive for us to recommend one product or service over another except where it best fits operational needs. We have the latest scenario planning software so we can drill even the most difficult wells by detailing anticollision analysis, well profiles, drill path projections, survey computations, hydraulics and hole cleaning calculations, torque and drag modeling, and BHA modeling. In the past few years there has been a trend for directional drilling assemblies to be very sophisticated. In some cases, this can be justified by increasingly complex targets which require the use of 3-D rotary steerable systems. But in other cases such as simple build and turn sections, a steerable assembly may be a more cost-effective solution. It's also worth remembering that in tangent or drop off sections, a 2-D rotary steerable or adjustable stabilizer is hard to beat. Wellbore inclination can be controlled without the need to trip for BHA modifications. It's always a question of planning directional changes efficiently."

To illustrate this approach let's run through a typical 121/4-in. section. In this case a well was designed for BP, in the Green Canyon Block, Gulf of Mexico (GOM). One of the areas that was identified as a potential cost saving was the 121/4-in. section. Instead of planning directional changes during the drilling of this section, it was designed as a straight tangent with directional requirements made in the 141/2-in. section.

Consequently, this enabled the 3,691 ft (1,125 m) 121/4 section to be directionally drilled by a conventional BHA assisted by an Andergauge adjustable stabilizer. The planned requirement was to hold both inclination and azimuth at 34? and 41.5? respectively. The results speak for themselves:

• The section was drilled from 14,395 ft (4,390 m) measured depth to 18,086 ft (5,516 m) measured depth at a rate of penetration (ROP) of 85 ft/hr.
• Average dogleg was 0.12? across the section.
• A smooth well bore was achieved and no problems were encountered while tripping.
• Four successful logging runs were conducted including MDT's and side-wall cores.
• No wellbore-related problems were reported.

Zane Nixon drilling engineer said, "We have evolved with the GOM industry. Our technical expertise grew from having drilled wells in the shelf and deepwater. Now we are designing ultradeepwater wells. These wells are so technically and financially challenging that only companies and products with track records can enter. We have delivered many projects in the GOM over the last 18 years. By focusing on Gulf Deepwater Coast and GOM directional drilling, we are able to keep things simple and concentrate on our core business. This, in turn, keeps overheads low, enables us to form excellent business relationships with other vendors, and provide better service and value to our customers."

Comments