Well cementation cement sheath integrity simulation and evaluation tester

Abstract

A well cementation cement sheath integrity simulation and evaluation tester includes pressing joints, wherein the pressing joints are arranged on compress packings; screwing compression rings are connected with compress discs through screw threads, and fix trapezoid rubber seal rings onto the compress discs and a steel tube; the steel tube containing a well cementation cement solidified body test sample is clamped tightly by screw rod and screw nut connecting assemblies and connected with the screw rod and screw nut connecting assemblies into a whole; pressing blocks and a mechanical pressure device are connected together to exert mechanical extrusion force to simulate the process that underground pressure variation causes damage and micro cracks to an oil well cement sheath; the pressing joints and a fluid pressing device are connected, so as to exert fluid pressure, simulate fluid pressure of the formation fluid on the well cementation cement sheath, and test and evaluate anti-channeling strength of the well cementation cement sheath; cured samples are placed in the well cementation cement sheath mechanical property simulation tester for test and analysis; and the tester can detect variation situations of the anti-channeling strength of the well cementation cement sheath under different conditions, so that impacting ductility and packing reliability of the well cementation cement sheath can be evaluated accurately.

Description

technical field [0001] The invention belongs to the technical field of petroleum drilling, and in particular relates to a simulation evaluation tester for cement sheath integrity. technical background [0002] During cementing construction, cementing cement slurry is injected into the annular space between the casing and the formation, and the cement slurry has to withstand the downhole environment and finally solidifies to form a cement sheath with certain cementing ability and hardness. The cement sheath in the well has the functions of effectively sealing off the formation and supporting and protecting the casing. In order to stabilize and increase production, all oilfields have successively carried out downhole engineering operations such as water injection, fracturing, acidizing, and refilling to increase the production pressure difference. Changes in temperature and temperature stresses caused by wellbore temperature changes will change the stress state of the cement ...

AI Technical Summary

Problems solved by technology

[0011] These research methods all strive to simulate the downhole stress of the cement sheath as much as possible, but the existing problems are that the test equipment is complex and huge, and the test cost is high

These existing methods can only measure the mechanical properties of the cement sheath under specific conditions, but cannot quantitatively analyze and measure the change of the downhole pressure on the channeling strength of the cement sheath, making it difficult to understand the essence of the problem

Images