The Development and Field Testing of a High-Temperature Deep-Layer Open Hole Packer for Acid Fracturing Completion in Deep Carbonate Reservoirs

Premature aging of packer rubber elements and damage-prone of packer skeletons during the open hole well completions have been a problem in the deep Ordovician reservoirs of Northern Tarim Basin. To solve this, the causes of failures have been analyzed, after which a flexible anchor slip structure was designed for the protection of steel skeleton and prevention of damage to the rubber element caused by the excessive deformation of steel skeleton under large expansion ratio and high pressure. While maintaining the excellent aging resistance of fluororubber, plasticizing modification technology was used to improve its plasticity and thermal stability, which would make it easier to be moulded through mold injection. For the fluid inlet channel of the setting mechanism, a ball-activated protective sliding sleeve was designed to avoid the settling and clogging of drilling fluid. The improved open hole packer had a temperature resistance of 180 ℃ and strong sealing capacity, which was suitable for long-term sealing of irregular open hole formations. When applying such improved open hole completion packer in 4 wells in the Halahatang Area of Northern Tarim Basin, the RIH was smooth, the setting sign was obvious, and there was no abnormal casing pressure during the large-scale acid fracturing and production process. Research results showed that the improved packer met the needs of the integration of completion, acid fracturing and production testing, solved problems of deep oil and gas development in Tarim Basin, and had a good value for popularization and application.