Relief well real-time orientation calculation and error correcting method and system

Abstract

The invention relates to a relief well real-time orientation calculation and error correcting method and system. The relief well real-time orientation calculation and error correcting method comprisesthe following steps: 1, placing an underground electromagnetic detecting instrument in a first depth sampling point and a second depth sampling point in a relief well to obtain the relative distancebetween a corresponding accident well casing pipe and the relief well; 2, establishing a two-point geometry positioning method model of the accident well casing pipe and the relief well; 3, when the real-time well deviation angle is less than or equal to the well deviation angle threshold value, entering the step 4, and when the real-time well deviation angle is greater than the well deviation angle threshold value, entering the step 5; 4, setting the distance between the first depth sampling point and the second depth sampling point to be greater than L, and calculating the orientation information between the accident well casing pipe and the relief well; and 5, setting the distance between the first depth sampling point and the second depth sampling point to be less than L, and calculating the orientation information between the accident well casing pipe and the relief well. The relief well real-time orientation calculation and error correcting method can be widely applied to the technical field of underground detection.

Description

technical field [0001] The invention relates to a method and system for real-time azimuth calculation and error correction of a rescue well, belonging to the technical field of downhole detection. Background technique [0002] In the process of offshore and land drilling, accidents such as oil and gas well fire, blowout out of control and oil leakage will not only cause serious economic losses, but also make environmental pollution more and more serious. At present, drilling rescue wells is one of the most effective ways to solve blowout accidents, and accurate detection of the azimuth information of the accident well casing in rescue wells is a key way to control blowout accidents and ensure safe deepwater drilling operations. [0003] In recent years, the method of measuring the relative distance and orientation between rescue wells and accident wells has attracted extensive attention from scholars at home and abroad. The prior art discloses the method of using the magnet...

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Problems solved by technology

However, this method requires a high-power current source, and the conductivity of the formation has a great influence on the received signal. If the formation resistivity at the detection end is high, the current converging on the casing of the accident well is very small, which seriously affects the accident. The detection accuracy of the well casing, and although this method can measure the azimuth, the azimuth information of the direct test is not accurate

[0004] Therefore, the transient electromagnetic method has become a development trend of current rescue well detection and positioning methods because of its non-contact measurement, high signal strength, large detection depth, and the ability to track distance characteristics in time. The metal casing is 6-7 orders of magnitude lower than the resistivity of the formation. By detecting the metal anomaly in the uniform formation, the relative distance and orientation of the rescue well and the accident well casing are determined. However, this method only gives the azimuth The theoretical model for calculation does not analyze the factors affecting the accuracy of azimuth calculation in combination with the actual test situation, so the solved azimuth error is relatively large, which cannot meet the needs of actual testing

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