Sand washing type fishing technology for sand prevention pipe string

Abstract

The invention discloses a sand washing type fishing technology for a sand prevention pipe string, which comprises the steps of 1) cutting off a blind pipe of a top sand prevention pipe section; 2) recovering a top packer; 3) running a sand washing pipe string into the residual sand prevention pipe string of the top sand prevention pipe section; 4) slowly putting down the sand washing pipe string, and simultaneously, circulating washing liquid to conduct sand washing for annular space between the top sand prevention pipe section and a casing pipe; 5) cutting off a blind pipe which is close to the lower portion of an intermediate isolation packer on the top currently; 6) fishing the residual sand prevention pipe string of the top sand prevention pipe section and an intermediate isolation packer at the bottom of the top sand prevention pipe section; and 7) repeating steps 3) -6) to fish out the residual sand prevention pipe string of the next sand prevention pipe section and an intermediate isolation packer at the bottom of the next sand prevention pipe section until all the sand prevention pipe sections and packers are fished out. The sand washing type fishing technology can solve the problem that conventional casing milling is difficult to adopt due to the small annular space between a screen pipe and the casing pipe, effectively speed up the fishing schedule, accelerate the operation effectiveness for a given period of time, control the expenses in a work period and save the operation cost.

Description

technical field [0001] The invention relates to a salvage process for sand control strings of oil and water wells, in particular to a sand flushing fishing process for sand control strings. Background technique [0002] Most of the oil and water wells in the Bohai Sea have severe sand production, and mechanical sand control of screens has become a routine treatment method. After years of production, sand control strings have failed due to various reasons. For the salvage of sand control pipe strings, the previous idea was to cover and mill sand control pipe strings in sections, and then knock down the buckle for salvage. However, for large-diameter sand control pipe strings, due to the small gap, the risk of casing milling operation is relatively high, and the conventional fishing method has many uncertainties, so it is impossible to accurately control the operation risk and construction period cost. Contents of the invention [0003] In order to solve the technical probl...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the technical problems existing in the known technology, the present invention provides a sand-flush type salvage process for sand control strings, which is used to solve the problem that the annulus between the screen pipe and the casing is small and it is difficult to adopt conventional casing milling

Images