Gravel pack sand prevention pipe column installed when wellhole is flushed, for horizontal well

Abstract

The invention discloses a gravel pack sand prevention pipe column installed when a wellhole is flushed, for a horizontal well. The gravel pack sand prevention pipe column comprises a flushing and preventing outer pipe column, wherein a sand flushing inner pipe column and a squeezing and packing sand prevention inner pipe column are arranged at the inner part of the flushing and preventing outer pipe column, the sand flushing inner pipe column is firstly loaded into the flushing and preventing outer pipe column, after the flushing work is completed, the sand flushing inner pipe column is pulled out, and then, the squeezing and packing sand prevention inner pipe column is put into the inner part of the flushing and preventing outer pipe column. According to the gravel pack sand prevention pipe column disclosed by the invention, the flushing and the sand prevention of the wellhole can be completed in an integrated manner, the sand prevention construction period of the horizontal well in a quicksand stratum is shortened, and the cost is saved; the wellhole is kept clean, the situation that the sand prevention pipe column successfully reaches a designed position is guaranteed, the closing of packing channels is reliable, and the success rate of the bottom squeezing and packing construction is increased.

Description

technical field [0001] The invention relates to a pipe string for downhole operation in oil production, in particular to a sand control pipe string for filling gravel while flushing and running down a horizontal well. Background technique [0002] As the development of unconsolidated sandstone reservoirs enters the middle and late stages, the degree of formation skeleton sand damage increases, and the degree of sand production intensifies in reservoirs with slight sand production in the early stage, forming some "quick sand" formations. Horizontal wells in such formations are undergoing downhole operations A large amount of formation sand will be gushed out of the ground, and the pipe string needs to be lowered several times before reaching the design position. gravel packing for sand control. At present, horizontal well gravel packing is carried out in "quick sand" formations, which takes a long time to occupy the well, and the success rate of gravel packing sand control co...

AI Technical Summary

Problems solved by technology

[0002] As the development of unconsolidated sandstone reservoirs enters the middle and late stages, the degree of formation skeleton sand damage increases, and the degree of sand production intensifies in the reservoirs with slight sand production in the early stage, forming some "quick sand" formations. Horizontal wells in such formations are in the process of downhole operations A large amount of formation sand will be gushed out of the ground, and the pipe string needs to be run repeatedly before reaching the design position. gravel packing for sand control. At present, horizontal well gravel packing is carried out in the "quick sand" formation, which takes a long time to occupy the well, and the success rate of gravel packing sand control construction is low, and the operation cost is high

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