Ultralow-permeation plugging anti-sloughing oil layer protective agent for drilling fluid and preparation method of protective agent

Abstract

The invention relates to an ultralow-permeation plugging anti-sloughing oil layer protective agent for a drilling fluid. The ultralow-permeation plugging anti-sloughing oil layer protective agent is characterized by consisting of the following components in percentage by weight: 10%-50% of a mineral fiber type material, 10%-50% of lignin fiber, 0%-15% of asphalt fiber, 20%-60% of low-softening point asphalt powder, 5%-10% of cellulose modified starch, 0%-5% of walchowite, 0%-5% of superfine calcium carbonate and 2%-8% of a modifying agent. The invention further relates to a preparation method of the plugging anti-sloughing oil layer protective agent. A sample obtained in the invention contains a plurality of deformable particles, including a high-temperature softening material, a bridge plug material, a water-swellable and fiber-deformation material and the like; and the sample has wide grain size distribution range, can plug fissures and holes in wide size range, can quickly form an ultralow-permeation shielding film, can reduce the amount of the drilling fluid flowing into the ground layer, can simultaneously protect storage layers, achieves good water dispersion stability, can be matched with a plurality of drilling fluids, simultaneously is simple in production technique, can satisfy the current environment, human body health and safety requirements, is low in cost and causes no adhesion problem in transportation.

Description

technical field [0001] The invention relates to an ultra-low permeability plugging and anti-collapse oil layer protection agent for drilling fluid and a preparation method thereof. Background technique [0002] With the continuous deepening of oil and gas exploration and development, the formations encountered are becoming more and more complex, such as pressure-depleted formations, fracture-developed formations, broken or weakly cemented formations, low-permeability reservoirs, deep wells with long open holes, complex mud shale and multiple sets The problems of downhole complex situations and accidents such as differential pressure sticking, drilling fluid loss and borehole wall collapse and formation damage are very prominent. External fluids are always in contact with different formations and fluids in the well, which can easily cause damage to oil and gas layers. Reservoir damage not only affects the initial production of oil wells, but also affects the degree of damage ...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the single-function characteristics of existing products and the shortcomings in the technical process, the present invention provides an ultra-low permeability plugging and anti-collapse oil layer protection agent for drilling fluid, and also provides its preparation method

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