New skiddable coiled tubing drilling tower
By Dev George, Houston
Managing Editor, Oil and Gas Online
BJ Services Company says its Well Services Division for Europe & Africa has designed and completed construction of a dedicated coiled tubing drilling (CTD) tower for Phillips Petroleum Company Norway (PPCoN). Built at the BJ Services base in Stavanger, Norway, the new CTD tower was custom-built for PPCoN to offer maximum flexibility demanded by CTD operations, so as to accommodate a range of larger equipment sizes, on a wide variety of different platforms.
Designed for flexibility
Although skiddable CT towers have been used for some time, most were designed primarily to operate on specific platforms. "The new BJ Services CT tower design sets a new standard because it is so flexible: it will operate on virtually any platform, can handle extraordinarily large equipment, and is even capable of performing limited pipe handling of jointed tubulars," said Alasdair Buchanan, Region Manager – Europe and Africa for BJ Services.
"One distinction is that this CT tower is not limited to CTD operations. It can also be used in standard well servicing work, which further illustrates its operational flexibility. In the CT tower, we are offering a safer, more flexible and efficient approach to coiled tubing drilling than ever before. And that's very important to Phillips, as well as to other operators that will want to take advantage of these benefits in the future," he added.
Reduced cost & risk of injury
The BJ Services' CT tower makes possible a fully free-standing, self-supporting CT operation to be carried out in a safe working environment, while using the injector at a considerable height. Even when drilling while fully overbalanced, having a lubricator, which is long enough to accommodate the drilling tools, offers an extremely high degree of operational maneuverability and improved well control.
The new CTD tower design incorporates two separate skidding systems: one for the main structure and one for the injector. The injector can also be turned on a swivel plate up to 60 degrees in either direction.
The incorporation of multiple skidding functions permits the new CTD tower to be rigged up wherever convenient. When used with the new swivel system for the reel, it is possible to set equipment down once and to perform service work on multiple wells, eliminating costly rig-up, rig-down procedures, the risk of injury that may be associated with these procedures and freeing up cranes for other tasks on the platform.
Limited pipe handling of jointed tubulars is made possible through the incorporation of a winch and traveling tong system. This system can also be used for stack, riser rig-up, and tool deployment, further reducing the need for cranes following the initial set-up.
Erection of the tower is safe, simple, and quick, with large landing and locking pins in each module. The internal stair system allows for safe, easy access to each level as the tower is stacked up.
Development & testing in Norway
BJ Services began the design and testing of the new CTD tower as a result of receiving a major contract from PPCoN earlier this year. The contract provides for a comprehensive package of coiled tubing drilling and well services in the Ekofisk Region, offshore Norway. To ensure safe and effective operation, BJ Services carried out testing of the new CTD tower by installing it on an Ekofisk platform.
PPCoN awarded the multimillion-dollar contract to support plans to drill two wells during 2000-2001 in the Ekofisk Field. Based on the results from the two first wells, additional CTD wells will be evaluated. These wells are mainly located in the Ekofisk Field, however, CTD technology is also being considered for use in the Eldfisk and Tor Fields.
The dedicated CTD spread, which utilizes state-of-the-art remotely operated NORSOK V16 pump units, features a pressurized A 60-rated control cabin, complete solids control unit, free-standing tower system, two HR 5100 injectors, soundproofed 5000psi operating pressure power pack, and 75-ton capacity swivel base for the reel.