Thin interlayer steam injection thermal production well mixing-proof well completion process

Abstract

The invention relates to a method for completing a thin interlayer steam-injection thermal-recovery well in petroleum engineering. The invention adopts the technical proposal that the method comprises the steps as follows: 1) a particular valve hoop is assembled with an external casing packer, and lengths and positions of tools arranged on a well completion string according to the oil well geologic condition after the drilling is completed; 2) a cementing truck is connected with a cementing head for cementing; 3) a bumping rubber plug is displaced to the position of a cementing shoe for bumping; 4) an inner cavity of a casing is decompressed, so that cement paste in a borehole can enter a cavity body through a one-way valve to drive a piston to compress a piston cylinder; pressure of the inner cavity of the casing is boosted for a certain period to drive the piston to compress the cavity body, so that the cement paste in the cavity body enters a flow passage of the cavity body leadingto the external casing packer through the one-way valve, thereby expanding and sealing the external casing packer; 5) the external casing packer is completely expanded and sealed to complete the construction through repeating the step 4. The method has the advantages that: the method realizes that the external casing packer is expanded and sealed by the cement paste in the borehole without changing the cementing process, increasing construction risk or increasing the construction period, and has prominent economic and technological benefits.

Description

1. Technical field: [0001] The invention relates to a well completion method for steam injection and thermal recovery wells with thin interlayers in petroleum engineering, in particular to a method for preventing channeling and completion of steam injection and thermal recovery wells with thin interlayers. 2. Background technology: [0002] combined with Figure 4 , 5 , the current general well completion measure for thermal steam injection wells is ground anchor prestressing-cementing and perforation. The process is realized as follows: [0003] 1. attached Figure 4 An anchor [a5] is connected in series at the bottom of the casing [a1]. First, the anchor is fixed with cement, and the upper cement slurry is circulated through the cementing hole [a3] to control the cement surface below the circulation hole [a3]. The cement stone [a4] of the cement slurry after the cement solidifies makes the entire casing string anchored in the wellbore. [0004] 2. attached Figure 5 Cem...

AI Technical Summary

Problems solved by technology

Steam injection thermal recovery is easy to channel between layers

[0007] (2) The perforation operation will crush the cement sheath, making the isolation invalid and causing water channeling

[0008] (3) Although the ground anchor prestress can effectively prevent the expansion stress of the casing during steam injection thermal recovery, the completion process is complicated and the well construction period is extended by more than 3 days

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