The First Real Time Logging with Coiled Tubing Tractor in an Extended Reach Horizontal Well with Proof of True Stimulation

Abstract

Abstract The world's first successful application of a wired motor head assembly to allow real time logging with a tractor in an extended reach open hole horizontal well has been recorded in Saudi Arabia. The well, located on one of two finger islands, was completed to a total depth of 29,897 ft. (9.11 km) MD; making it the deepest well with open-hole section in the field development, and outside of the reach of traditional tapered coiled tubing (CT) used for well intervention. Using 2 inch tapered coil tubing and well tractor, the well was successfully acid-stimulated in 14 stages with a total of 3,850 barrels of (diesel) emulsified HCl acid recipe. This paper shows that although tractor interventions have a proven record and are the preferred deployment method for extended well stimulation, there still existed the uncertainty of conducting real time production logging while simultaneously tractoring. This additional challenge in the industry could be overcome by utilizing real time Electrical to Optical (EtO) production logging measurements simultaneously with the running of a tractor. A comparison of the pre- and post-stimulation injectivity indices on a separate run prior to the real time production log acquisition showed an eight fold injectivity index improvement from 53 bpd/psi to 400 bpd/psi. The resulting marked injectivity improvement from acid stimulation also showed the benefit of informed decisions from real time fiber-optic distributed temperature system (DTS) in fluid placement. Practical applications of these outcomes include the acquisition of real time data of comparable quality with conventional e-line tools resulting in distinct technical and economic advantages in the development of the remaining parts of the field. Others include the reduction in total well delivery costs from an ability to accurately evaluate well performanceand diagnose problems in real time. The ability to employ real time information to effectively stimulate extended reach wells provide assurance that stimulation can serve as a technical and an economic solution for addressing the relatively high skin damage problem post drilling and completion. Real time logging with the tractor is logistically efficient and allows real time acquisition of injection profiles with the possibility for improving data quality with return passes.