Oilfield downhole depth measurement device and method

Abstract

The invention belongs to the field of oilfield downhole working tools, and particularly relates to an oilfield downhole depth measurement method. The oilfield downhole depth measurement method refersto an upper joint, a piston sleeve, a piston, a central pipe, a spring protection sleeve, a spring, a lower joint and a sealing ball. The upper joint and the lower joint are connected to the upper andlower ends of the central pipe through threads correspondingly; the upper end of the piston sleeve is connected to the outer side of the upper joint through a thread; the piston is arranged in an annular space between the piston sleeve and the central pipe; a liquid passing hole is formed in the position, corresponding to the piston, on the central pipe; after pressure is pumped into the centralpipe, high pressure liquid enters a sealed space in the upper side of the piston through the liquid passing hole, and then the piston is pushed to move; and an elastic hanging claw is arranged on thelower portion of the piston sleeve, and a bulge is arranged on the outer side of the lower end of the elastic hanging claw. The precise depth of related downhole tools is measured by looking for a casing hoop, and the characteristics of simple structure and convenient use are achieved.

Description

Technical field [0001] The invention belongs to the field of oilfield downhole operation tools, and in particular relates to an oilfield downhole depth measuring device and method. Background technique [0002] In the process of downhole operations in the oilfield, the downhole tools are lowered to the designed depth. Due to the influence of the tubing measurement error, the tightness of the tubing thread, the elongation of the tubing string, the liquid buoyancy, etc., the depth of the downhole tool will be biased, and the deviation value is generally Within ±0.5m, this deviation range can meet the operating requirements in most cases. But when there is a precise requirement for the depth of downhole tools, precise depth correction is required. In the prior art, there is also a method for measuring the depth of downhole tools through magnetic positioning logging. However, this logging method has a relatively high logging cost and a relatively large technical difficulty, and the ...

AI Technical Summary

Problems solved by technology

In the prior art, there is also a method of measuring the depth of downhole tools through magnetic positioning logging, but the logging cost of this logging method is relatively high, the technical difficulty is relatively large, and the measurement accuracy needs to be improved

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