Double-seal straddle formation testing method

Abstract

The invention relates to a double-seal straddle formation testing method. The method comprises the following steps of (1) performing perforation on a first testing well section; (2) assembling a single-seal testing string into a well; (3) performing pulling out after completing the test of the first testing well section; (4) performing perforation on a second testing well section; (5) assembling adouble-seal straddle testing string into the well; (6) setting an anchor packer above a corresponding first stratum in a sleeve, then setting a straddle packer, and then performing mechanical lockingand anchoring to the sleeve; (7) opening a tester, enabling formation fluid of the second testing well section to enter a test string from a screen pipe II, and enabling the formation fluid to flow upwards through the tester; (8) performing pumping analysis; (9) closing the tester, and enabling second formation fluid to remain in the string; (10) lifting the string, unanchoring mechanical locking, and then sequentially unsetting the straddle packer and the anchor packer; and (11) lifting oil pipes one by one, and performing sampling when the second formation fluid in the string is seen. According to the testing method, two well sections can be continuously tested in sequence, the testing time is greatly shortened, and the testing efficiency is improved.

Description

technical field [0001] The invention relates to an instrument for downhole testing, in particular to a method for testing double-sealed straddle formations, which belongs to the technical field of oil and gas testing. Background technique [0002] In the process of oil exploration, oil, gas and water layers can be preliminarily determined through cuttings logging, gas logging, core analysis and electrical logging interpretation data, but they need to be verified by oil testing in the end. Formation testing, also known as drill string testing, is a key link in scientific oil testing. It plays an important role in determining reservoir productivity, fluidity, energy, and reservoir seepage characteristics and parameters, and can provide reliable data for further exploration and development of blocks. Detailed basis. [0003] Before formation testing, the test well section is perforated, that is, the perforating gun is lowered to the test well section, and the casing of the wel...

AI Technical Summary

Problems solved by technology

[0005] Since the cement plug needs to be accurately injected into the downhole cement slurry, it needs to wait for 48 hours for solidification after the grouting is completed, and the sealing performance must be verified after solidification; after the test is completed, the drilling tool must be lowered to drill the cement plug, so that the time required to complete the two-layer test is relatively short. Long, low test efficiency, and many processes, high risk

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