Double-seal straddle test string

Abstract

The invention relates to a double-seal straddle test string. The double-seal straddle test string comprises a screen pipe I corresponding to a first stratum and a screen pipe II corresponding to a second stratum, wherein a pressure gauge supporting cylinder I is connected to the lower part of the screen pipe I in a screwed mode, a slip packer, a lifting short section I and a screwed plug are sequentially arranged above the screen pipe I, and the upper end of the screwed plug is connected with the bottom of the screen pipe II through an adjusting short section. The screen pipe II is upwards connected with a pressure gauge supporting cylinder II, a straddle packer, a lifting short section II, a mechanical lock, a tester, a lifting short section III and a circulating valve in sequence; and the straddle packer comprises a bypass mechanism, wherein a setting mechanism is arranged below the bypass mechanism, a shear pin mechanism is arranged below the setting mechanism, and a transposition mechanism for controlling bypass and setting is arranged below the shear pin mechanism. The double-seal straddle test string disclosed by the invention can be used for continuously testing two well sections in sequence, so that the test time is greatly shortened, the test efficiency is improved, and the test accuracy is high. In the well descending process, it is ensured that the straddle packer cannot be set in advance, and the success rate of straddle testing is increased.

Description

technical field [0001] The invention relates to an instrument for downhole testing, in particular to a double-seal spanning testing string, which belongs to the technical field of petroleum and natural 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 well s...

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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