RTP Rehabilitation Strings
- Extending the life of wells in aged fields has been proven to be a superior means of field production cost efficiency compared to developing new production wells. Operators lose billions of dollars to corrosion of steel tubing strings of well completions in old wells, with a premature end to well life cycle.
- Besides the low corrosion resistance of carbon steel tubings/casings, the major contributing factors are untreated seawater injection (carries SRB bacteria causing an increase in H2S level) and a higher CO2 content in produced fluids. These factors result in significant corrosion damage on carbon steel downhole casing and tubing strings, and production loss.
- Our reinforced thermoplastic (RTP) rehabilitation string features a PVDF liner, Aramid glass/carbon fibre reinforcement and a PVDF cover, and can be used in applications up to 3,000 psi maximum allowable operation pressure and up to 212°F maximum allowable operation temperature. It is lightweight, spoolable and manufactured in long, continuous lengths, enabling high speed deployment with commonly available equipment designed for steel coil tubing, which is key to facilitate installation, especially offshore. This RTP string can be used in the rehabilitation of a wide range of downhole tubulars with breach due to corrosion.
In successful applications in Asia Pacific since 2013, our customer worked with us to qualify our RTP string for rehabilitation of corrosion-damaged steel tubing downhole. A comprehensive qualification test program was developed covering all the load cases that the RTP rehab string would see during installation and in operation. Upon successful qualification tests, our customer selected offshore wells, including injection and production wells that had multiple breached locations in their carbon steel downhole tubing, and had been shut down for two years. After inspecting the existing downhole tubing and identifying the locations of corrosion damage, 2” RTP rehab strings were deployed with top and bottom packers, providing a new flow path for the bore fluid and isolating the corroded portion. The offshore deployments were completed successfully, each within two weeks. These wells have been in service without any issue since then.