Oil well cement composition and application thereof

Abstract

The invention discloses an oil well cement composition and an application thereof. The oil well cement composition is prepared from the following components in parts by weight: 100 parts of G-grade oil well cement and 15-30 parts of cement kiln ash. Optionally, the oil well cement composition can further comprise 1-5 parts of a suspending agent, 5-15 parts of an early strength agent, 5-10 parts ofan ultrafine material and 1-5 parts of an expanding agent. The density of the cement paste prepared from the oil well cement composition is adjustable between 1.4 g / cm<3> and 1.6 g / cm<3>, the cementpaste formula is simple in composition, high in paste making rate, high in compressive strength and good in sedimentation stability, the field construction requirement can be met without adding floating beads and the like to reduce the material performance, the cost is low, and construction is convenient. The construction problems that in the prior art, well cementation hollow floating beads and microbead cement paste of a full-sealing section of a low-pressure leaky stratum and a low-pressure oil-gas layer are high in cost, limited in pressure bearing capacity, low in paste making rate, largein ash demand, limited in site ash storage space, incapable of achieving full sealing and the like are solved.

Description

technical field [0001] This article relates to the field of exploration and development of oil and gas fields, especially an oil well cement composition and its application. Background technique [0002] With the development of exploration and development of oil and gas fields, higher requirements are put forward for modern cementing technology, especially the increasing number of complex wells, long-sealed well sections and low-pressure leak-prone wells, and the problems in cementing are becoming more and more complicated. . Among them, cement slurry leakage is the main problem that generally exists. Cement slurry loss refers to the entry of all or part of the drilling fluid, cement slurry and completion fluid into the formation during the drilling and completion process. Cement slurry leakage and low return is one of the common and unresolved technical problems in oilfields at home and abroad, especially in the cementing construction of multiple sets of pressure formatio...

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Problems solved by technology

It solves the problem of the high cost of cementing hollow floating beads and microbeads in the cementing section of low-pressure leaky formations and low-pressure oil and gas layers, the high cost of cement slurry, the limited pressure bearing capacity, the low slurrying rate, the large amount of ash required, and the limited on-site ash storage space. Full sealing and other construction problems

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