Self-adaptive casing centralizer and righting method

Abstract

The invention discloses a self-adaptive casing centralizer and a righting method. The self-adaptive casing centralizer comprises a body. A plurality of self-adaptive expansion assemblies capable of being automatically expanded by pressure to automatically adapt to the diameter of a well to right and fix a casing are arranged on the body. Each self-adaptive expansion assembly comprises a bellows arranged in a stepped through-hole slot. The cross section of each bellows is in a wavy shape. The self-adaptive casing centralizer is simple in whole structure and convenient to operate and can adapt to different well diameters, the casing is effectively righted and fixed, and the well cementing quality is improved; the overall outer diameter of the body of the self-adaptive casing centralizer is smaller than the well diameter of a wellbore when the body of the self-adaptive casing centralizer is in an initial state, the centralizer can smoothly enter the well, the risk of encountering resistance is reduced, the well wall is not damaged, the bellows can uniformly expand, the supporting force is improved, the casing is effectively righted, and the centering degree of a casing column is increased; and after centering of the casing is completed, the wellbore annular clearance is uniform, the well cementing quality can be effectively improved, and the whole construction is easy and convenient.

Description

technical field [0001] The invention relates to a casing centralizer and a centralizing method, in particular to a self-adaptive casing with simple structure, convenient operation, adaptability to different well diameters, effective centralization and fixing of the casing, and improvement of cementing quality A centralizer belongs to the technical field of oil and gas drilling and completion. Background technique [0002] The casing centralizer is one of the important devices commonly used in the field of oil and gas drilling. Its function is to make the casing live in the center of the wellbore, ensure the centering of the downhole casing, and improve the cementing quality. [0003] Existing traditional centralizers mainly include elastic centralizers and fixed centralizers. For example, the patent number is: 201520678554.7 discloses an adaptive casing centralizer, which includes a main body with a cylindrical structure, and an annular hollow is arranged in the side wall of...

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Problems solved by technology

[0004] The above-mentioned casing centralizers can effectively adapt to different wellbore diameters, but this type of centralizer has a large size and poor self-adaptive ability, which may easily cause obstruction or cementing quality in complicated wellbore casings during lowering. The poor problem affects the lowering ability of the casing, and the casing centering effect is poor, which greatly affects the cementing quality, and the structure of this type of centralizer is complicated, the manufacturing process is cumbersome, and the manufacturing cost is seriously increased

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