Device and method for detecting density change of foamed cement with pressure

Abstract

The invention provides a device and method for detecting the density change of foamed cement with pressure, and the device comprises a high-pressure sampling short section and a pressure relief discharge short section; the high-pressure sampling short section comprises a high-pressure sampling pipe, and a first throttle valve and a second throttle valve which are connected to two ends of the high-pressure sampling pipe; the pressure relief discharge short section comprises a pressure relief discharge pipe connected with the second throttle valve and a pressure relief valve connected to the pressure relief discharge pipe. The method comprises the following steps: after the first throttle valve of the device for detecting the density change of foamed cement with pressure is mounted on a bypass valve of the high-pressure pipe, guiding the high-pressure foamed cement slurry fluid into a high-pressure sampling cavity; obtaining the pressure in the high-pressure sampling cavity and the massof the high-pressure foamed cement slurry fluid in the high-pressure sampling cavity; calculating the density of the high-pressure foamed cement slurry fluid under the pressure P in combination with the internal volume of the high-pressure sampling cavity; and after releasing part of the pressure of the high-pressure sampling cavity, recalculating the density. According to the invention, the density change of the foamed cement slurry fluid with pressure can be obtained.

Description

technical field [0001] The invention relates to the technical field of the variation law of foam cement density with pressure, in particular to a detection device and a detection method for foam cement density variation with pressure. Background technique [0002] Foamed cement slurry is widely used in the field of oil drilling and completion due to its unique low density and compression characteristics. Foamed cement slurry belongs to the category of gas-liquid two-phase flow, and its density is sensitive to changes in temperature and pressure. At present, due to the inaccurate gas phase model There are still large errors in the calculation of the density of foamed cement slurry by using the physical property model. In the engineering field, only by accurately predicting the density of foamed cement slurry under different pressures can we take appropriate technological measures and achieve better construction results. . [0003] Both Chinese patent publications CN101526445...

AI Technical Summary

Problems solved by technology

[0002] Foamed cement slurry is widely used in the field of oil drilling and completion due to its unique low density and compression characteristics. Foamed cement slurry belongs to the category of gas-liquid two-phase flow, and its density is sensitive to changes in temperature and pressure. At present, due to the inaccurate gas phase model There are still large errors in the calculation of the density of foamed cement slurry by using the physical property model. In the engineering field, only by accurately predicting the density of foamed cement slurry under different pressures can we take appropriate technological measures and achieve better construction results.

[0003] Chinese patent publication CN101526445A and CN202676565U all can only measure the density under fixed pressure, can not measure the density of foam cement slurry and cement stone under different pressures

[0004] The device involved in the Chinese patent publication CN102539280A has the function of self-pressurization and heating, and is tested by electronic control. The structure is complicated, the operation is complicated, and the cost is high.

[0005] The density measurement device involved in the US patent publication US5974858 must be installed on the pipeline to be tested, and cannot be continuously pressurized, and can only passively measure the density under temperature and pressure here.

[0006] It can be seen that there are currently no mature devices and equipment specifically for measuring the density of foamed cement slurry. It is an urgent task in this field to develop a mature device that can measure the density of foamed cement slurry

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