Pressure testing method for segmented oil pool and segmented trial-squeezing tubing string

Abstract

The invention provides a pressure testing method for a segmented oil pool and a segmented trial-squeezing tubing string. The segmented trial-squeezing tubing string comprises a hydraulic anchor, a Y111 type packer, an oil pipe adjusting short section, a pressure guiding sand blower, a Y211 type packer and a guider which are sequentially connected in series. The hydraulic anchor is connected with an oil pipe through a safety joint. A wellbore and a blocked reservoir stratum nearby cracks are cleaned through blockage removing fluid, the initial transformation situation is judged to serve as a subsequently conducted repeated fracturing design basis, the average time of single-segment trial-squeezing pressure testing is 3 h, the testing period is effectively shortened, and the construction efficiency is improved; the calculation method is simple and rapid, and no special interpretation software is needed; and the problems that direct segmented oil pool pressure testing conducted on a horizontal well is long in consumed time, high in cost and the like, and the segmented oil pool pressure of the horizontal well cannot use the vertical well testing method are solved, so that the testing period is shortened.

Description

technical field [0001] The invention relates to the field of oil production engineering, in particular to a segmented oil reservoir pressure test method and a segmented test extrusion tubing string for fractures in an old well of a low-permeability oil reservoir horizontal well before recompression. Background technique [0002] Low-permeability reservoirs usually need to be effectively developed by adopting the "horizontal well + staged fracturing" stimulation method, and the initial single-well production can usually reach 8-10 tons. However, with the prolongation of time, due to the low degree of initial stimulation or the inability to establish effective displacement in the reservoir, the productivity of a single well in the initial period decreases by 20% to 30% every half year, and by 30% to 50% after one year. The decline is still as high as more than 40%, the production decline is large, and the proportion of low-production wells accounts for more than 30%. [0003]...

AI Technical Summary

Problems solved by technology

This technology belongs to the direct test of wellbore production flow pressure, and cannot be used for reservoir pressure test

To obtain the reservoir pressure, it is calculated based on the pressure recovery time of 15-20 days for each well shut-in, and the average time for each well is 120-160 days. data distortion

At the same time, this technology is only applicable to high liquid volume horizontal wells. For low liquid volume horizontal wells, the segmental pressure calculation error is relatively large, and each segment needs to be interpreted by special reservoir pressure interpretation software, which takes a long time and costs high

For repeated stimulation of horizontal wells, the utilization rate of oil wells is low, and it is not representative for obtaining horizontal well segmented reservoir pressure

[0005] To sum up, the existing methods for obtaining pre-fracture reservoir pressure tests have the following problems: First, the direct pressure recovery test of this well is mainly applied to vertical wells, and for horizontal wells exploited in multiple stages, the difference in reservoir pressure between stages cannot be directly judged

Second, the adjacent well pressure recovery test is not suitable for heterogeneous reservoirs, especially for horizontal wells

Third, the current method of horizontal well pressure testing is mainly used for segmented fluid production and flow pressure testing. Not only can the reservoir pressure not be obtained, the construction period is long and the tool stability is poor, and it is impossible to identify whether the cause of the low production contribution section is clogging or In the early stage, it was not modified due to tool failure

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