BJ Services Installs First InjectSafe Chemical Injection System with Capillary Strings Offshore in Europe
BJ Services Company announced that it has successfully installed the first InjectSafe™ chemical injection system with DynaCoil™ capillary injection strings offshore in two wells in Europe. Installation of the InjectSafe and DynaCoil systems allowed BJ to inject foaming agent directly downhole through the capillary string, without compromising the integrity of the surface-controlled subsurface safety valve (SCSSV). The foaming agent, which foams condensate produced from the well, prevents liquid from accumulating in the well and enables production to flow continuously, resulting in an increase in overall gas production rates.BJ Services carried out the project in the North Sea with operational support from its base in Aberdeen.
The InjectSafe system is a unique technology developed by BJ Services to allow wells to retain SCSSV integrity and operability by preserving the existing control line function, while allowing injection of fluids directly to the wellbore below the SCSSV. The system is run in conjunction with DynaCoil capillary injection tubing using specially engineered capillary tubing equipment. This equipment is designed specifically for running small-bore tubing into wells and features, among many advantages, a small wellsite footprint to reduce impact upon other platform operations.
The method of installing an InjectSafe system is usually straightforward. The existing tubing-retrievable SCSSV is locked open and the InjectSafe system, featuring a BJ Services’ FlowSafe™ SCSSV and capillary string assembly that is long enough to reach the predetermined depth, is run in the well on wireline, then set and locked in place. A stinger attached to the upper capillary string is then run into the well, using a special injector head, until the stinger locates in the downhole receptacle within the InjectSafe SCSSV system. This establishes fluidic communication from the surface, around the safety valve, and to the bottom of the well, enabling chemical or foamer injection to take place. Integrity, through the capillary string, is maintained by four check valves located within the system. These prevent any backflow from the well being able to reach surface through the capillary string. Two are located in a bottomhole assembly, one within the InjectSafe TM SCSSV body and one inside of the stinger.
Pioneering the Way Forward
The recent InjectSafe installation is the first time that BJ Services has employed this technology offshore in Europe. “By installing this system offshore we can economically treat wells prone to production-related issues such as liquid loading, salting, waxing, scaling and hydrate problems,” said John Anderson, Region Vice President – Europe & West Africa for BJ. “These conditions can now be treated without pulling the tubing to install a capillary string, which would be a more expensive and time-consuming option,” he added.
About the InjectSafe™ System
The InjectSafe TM SCSSV system allows effective downhole treatments by enabling the installation of small diameter capillary strings within the production tubing to apply specialty treatments to enhance production without compromising the capability of the SCSSV. The capillary strings can be run to depths of 22,000 ft (7,000 meters).
Surfactants and foamers can be used for deliquification in gas wells while chemical inhibitors can be injected to protect tubulars and lower completions from corrosion and scale deposits, or to inhibit precipitation of salts, asphaltenes and paraffin in the tubing and SCSSV. By injecting de-emulsifying chemical at the perforations, emulsions are much less likely to form. Using the InjectSafe system results in more productive wells, more completely produced reservoirs, and safer platforms.
In 2007, BJ Services received a Meritorious Award for Engineering Innovation from E&P magazine in recognition of the InjectSafe system.
