How to carry out hydrostatic test of oil casing?

How to carry out hydrostatic test of oil casing?

Special oil pipe is mainly used for drilling oil and gas wells and transporting oil and gas. Oil casing is mainly used to support the well wall during and after well completion, so as to ensure the normal operation of the whole oil well during the drilling process and after completion. Oil casing is the lifeline of oil well operation. Due to the different geological conditions, the downhole stress state is complex. The comprehensive action of tensile, compressive, bending and torsional stresses on the pipe body puts forward higher requirements for the quality of the casing itself. Once the casing itself is damaged due to some reason, the production of the whole well may be reduced or even scrapped.

The hydraulic testing machine for oil casing is used to test the pressure bearing pressure of casing. The test pressure is 70MPa, 9 5 / 8 ",. 7", 5 1 / 2 ", 5", 4 1 / 2 ", 3 1 / 2", 27 / 8, etc. The method of supercharging cylinder is adopted to pressurize, which is fast and reliable, and equipped with automatic control system, which can display the pressure curve in real time, output the test lecture and retain the experimental data.

According to the strength of steel, oil casing can be divided into different steel grades, namely J55, K55, N80, L80, C90, T95, P110, q125, V150, etc. Different well conditions and depths lead to different steel grades. In the environment of corrosion, the casing itself is required to have anti-corrosion function. It is also required that the casing has the function of anti collapse when the geological premise is complex. Oil casing is a kind of steel pipe used to support the well wall of oil and gas wells, so as to ensure the abnormal operation of all oil wells after well completion. How many layers of casing should be used in each well according to different drilling depth and geological conditions. Different from tubing and drill pipe, it can not be used repeatedly and belongs to disposable consumption data. Therefore, the consumption of casing accounts for more than 70% of all oil well pipes. According to the application situation, casing can be divided into: conduit, surface casing, skilful casing and reservoir casing.