Sulfur removal coiled tubing drag reducer

Abstract

The invention discloses a drag reducing agent for sulfur-removing coiled tubing, which comprises 0.5-10% of organic sulfur-removing agent, 0.1-2% of metal drag-reducing agent, 1-2% of clay stabilizer, 0.5% ~4% of corrosion inhibitor, and the balance of water or hydrochloric acid solution; wherein, the metal drag reducer includes 5~15% of swire oil by mass fraction, 15~40% of nonionic surfactant, 10~ 20% small molecule glycol and the balance are water; the clay stabilizer is the benzyl quaternary ammonium salt obtained by the reaction of triethanolamine and benzyl chloride; the corrosion inhibitor is a commercially available pyridine quaternary ammonium salt corrosion inhibitor; the Sulfur-removing coiled tubing drag reducer is suitable for various downhole working fluids with a pH value between 1 and 12. The temperature resistance is as high as 120°C, the anti-swelling rate is >90%, the sulfur removal capacity is >150,000mg / L, and the salinity is high. The bearing capacity value can reach up to 30000mg / L. At the same time, the addition of the drag reducer can reduce the friction coefficient between metal materials from 0.74 to 0.12. It is suitable for preparing fracturing fluid, acid fluid, perforating fluid and workover Additives for various downhole working fluids.

Description

technical field [0001] The invention relates to the technical field of downhole operations in exploration and development of oil and gas fields, in particular to a sulfur-removing coiled tubing drag reducer. Background technique [0002] In the field of downhole operations, the construction tasks of coiled tubing mainly include: coiled tubing cutting, salvage, sand washing and plugging removal during workover; , and drilling plug operations. Among them, for highly deviated wells or horizontal wells with long horizontal sections, the construction of coiled tubing is affected by the length of the horizontal section, the wellbore trajectory, the inclination angle of the horizontal section, etc., and the "locking" phenomenon of coiled tubing running often occurs. That is: during the process of coiled tubing entering the well, due to the buckling of the coiled tubing itself, it will rub against the inner wall of the steel casing during the horizontal section to generate resistan...

AI Technical Summary

Problems solved by technology

The low-concentration aqueous solution of this system can greatly reduce the friction coefficient between metal tubing strings, thereby reducing the self-locking degree of coiled tubing and increasing the extension length of coiled tubing in the horizontal section; There are certain deficiencies in the above, especially when the oil and gas layers have been opened and coiled tubing construction is required, such as when coiled tubing plugs are used after fracturing construction, in this case, the formation has been exposed, when the coiled tubing drag reducer and formation When clay is in contact, it is easy to make it expand and migrate, which will affect the permeability of the formation and cause pollution damage to the formation, further affecting oil and gas production; The generation of hydrogen gas or the generation of hydrogen sulfide gas during the acidizing operation will cause severe corrosion to the coiled tubing, resulting in a significant reduction in the strength of the coiled tubing, and in serious cases, it may break during construction, causing engineering complexity or engineering accidents