On-line continuous monitoring and sampling protection device for oil and water well casing external pressure

Abstract

The invention relates to an online continuous monitoring sampling protecting device for external oil-water well casing pressure. The problem that an existing casing is damaged by being extruded or broken is mainly solved. The online continuous monitoring sampling protecting device is characterized in that the upper portion of a pressure measuring sampling tube (4) is connected with a ground device (18), the lower portion of the pressure measuring sampling tube (4) is connected with a pressure sampling sampler (8), the ground device (18) is arranged at the position of an oil-water well mouth (27) and comprises a tee joint I (17), the lower portion of the tee joint I (17) is connected with a well shut-in valve (30), the lower portion of the well shut-in valve (30) is connected with the pressure measuring sampling tube (4), the upper portion of the tee joint I (17) is connected with a liquid injection exhaust and drainage valve (16), and a side face connector of the tee joint I (17) is connected with a pressure measuring recording instrument (14) and a sampling valve (13). According to the online continuous monitoring sampling protecting device, changes of the external casing pressure and changes of water quality components can be monitored in real time, so that corresponding measures are adopted before the casing is extruded or broke, and casing damages are avoided or reduced.

Description

technical field [0001] The invention relates to the field of oil fields, in particular to an online continuous monitoring and sampling of oil and water well casing external pressure for online real-time monitoring, real-time sampling, and protection of oil and water well casing from being squeezed or broken. protective device. Background technique [0002] In recent years, due to the increase of injection and production intensity in oilfields, there have been many casing damage areas in old oilfields. In some blocks, the number of casing damage wells accounts for about 50% of the total number of wells, and the range of casing damage is increasing year by year. At present, there is no uniform rule in the extrusion direction of the casing, and the overall height of the standard layer (Nen 2 section) is about 10 meters. "S" shape. In addition, the extrusion direction between adjacent wells is uncertain. In the same block, good wells and bad wells are alternately interrupted, ...

AI Technical Summary

Problems solved by technology

According to investigation and statistics, in wells with casing damage, about 60% of the casing deformation or dislocations are located in the standard layer (Nen 2 Member) of the oil field, and most oil fields have the standard layer (Nen 2 Member) at a depth of about It is between 600 and 1000 meters, and this standard layer is mainly tight argillaceous shale with bedding phenomenon. Tight argillaceous shale is generally impervious to water, but after long-term high-pressure water injection, multi-layered argillaceous shale will be formed. Cleavage phenomenon occurs between layers, resulting in slippage, squeezing or dislocation of the casing at this standard layer, causing casing damage, and at the same time, the casing repair cost is very high (generally 600,000 to 1,000,000 per well time), resulting in a lot of damage. big waste

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