Plug type sand control method for slim hole sidetracked well

Abstract

The invention provides a plug type sand control method for a slim hole sidetracked well. The method includes the following steps that S1, a production string is pulled out; S2, a sand washing string is placed in; S3, after the sand washing string is placed at a sand surface position, sand washing is conducted; S4, a sand control string is completed; S5, a pressure test is conducted on a surface pipeline; S6, a shaft is filled; S7, prepad fluid is used; S8, plug type gravel filling is conducted on the shaft; S9, displacement fluid is used; S10, waiting on cement setting is conducted; S11, plug drilling and plug reserving are conducted. A sand blocking column plug is formed in the shaft of a sand control target stratum through consolidation chemical sand control proppants in a low pumping pressure filling mode, formation sand is effectively blocked outside the shaft and prevented from entering the shaft; due to the fact that the permeability of the sand blocking column plug is about 2 micron<2>, formation fluid passing is not affected, the purposes of sand control and production maintenance are achieved, the problems that the construction risk of conventional high pumping pressure gravel filling is high, the quantity of low pumping pressure gravel filling is small, a continuous sand blocking barrier is difficult to form, and the sand control effect is not ideal are solved, the one-time success rate of the method applied to sand control of the slim hole sidetracked well is one hundred percent, and the time of single well continuous production exceeds 500 days.

Description

Technical field [0001] The invention relates to the technical field of oil production in oil fields, in particular to a plug type sand control method for side drilling of a slim hole. Background technique [0002] Sidetracking is an oil well wellbore structure that opens a window in a vertical well casing to drill a side hole. It adopts a liner suspension structure, and a small casing is used for cementing and perforation completion. Commonly used Ф139.7mm outer diameter casing suspension Ф95 .3mm outer diameter small casing. For loose sandstone reservoirs, sidetracking sand production is one of the more common types of sand production in oil fields. Sand control measures must be implemented to ensure smooth production. [0003] At present, sand control measures include hanging sand filter pipes for sand control, solution sand consolidation and mechanical or chemical gravel packing for sand control. Sand filter pipe sand control is a simple sand control method by running various t...

AI Technical Summary

Problems solved by technology

Although the sand control effect of gravel packing is outstanding, it is restricted by the wellbore conditions when it is applied in slim hole sidetracking, because the key to the success of gravel packing sand control lies in the design of sufficient gravel packing volume according to the reservoir conditions and sand production conditions. Therefore, during the filling process, the gravel forms a continuous sand-retaining barrier or artificial well wall in the near-wellbore area, so as to ensure the sand control effect. Therefore, the construction pressure of gravel packing is basically higher than the critical fracture pressure of the reservoir or close to the critical fracture pressure, but for small wells When sand control is carried out by gravel packing in side drilling, because there is a hanger in the wellbore, in order to protect the hanger, the current general practice is to control the construction pressure to less than 15MPa. If the filling volume is less than the designed filling volume, the sand control effect of the sidetracking well is not ideal, and sand will be produced again 1-2 months after commissioning, resulting in premature failure of sand control

At present, there are also small-diameter packers for sidetracking wells developed by oilfields, which are lowered into the slim wellbore below the hanger to protect the hanger from the construction pressure, realize gravel packing, and achieve good sand control effects. The construction pressure is high, and the risk of wellbore casing deformation under high construction pressure is further increased, and if there is a problem with the tool in the slim hole, it is very difficult to deal with it

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