High-strength gel for snubbing operation and preparation method of high-strength gel

Abstract

The invention relates to a high-strength gel for snubbing operation and a preparation method of the high-strength gel. The high-strength gel is characterized by being prepared from the following components in percentage by weight: 2%-5% of starch; 0.01%-0.1% of an oxidation-reduction initiator, 5%-13% of a cross-linking agent, 5%-20% of a cross-linking agent B, 10%-15% of an inimer, 0.015-0.1% of a curing agent and the balance of water. The preparation method comprises the steps; under the condition of stirring, dexitrinizing the starch in water in a proportion at a temperature ranging from 60 to 90 DEG C for 1-3 hours and then regulating the pH value of the solution to the range of 8-13 at the temperature of 30-150 DEG C; standing at constant temperature, sequentially adding the oxidation-reduction initiator, the inimer, the cross-linking agent A, the cross-linking agent B and the curing agent in a proportion, and uniformly stirring all the materials, and further standing, thereby obtaining the high-strength gel. The obtained high-strength gel has extremely high compressive strength and tube wall adhesion, is capable of meeting the basic property requirements of the snubbing operation on a gel system and controllable in gelation time, gel strength and viscosity, and has the characteristics of simple process, easily available raw materials and low cost.

Description

Technical field: [0001] The invention relates to a high-strength jelly for snubbing operation and a preparation method thereof, and belongs to the technical field of chemical agent application in petroleum drilling and completion engineering. Background technique: [0002] The snubbing operation is to complete operations such as tripping the drilling tool, coring under pressure, logging, running screens, running workover or completion strings under the condition of under-balanced pressure in the formation. This technology can further protect and maintain the integrity of the formation. In the original state, the purpose of preventing reservoir pollution and improving the development effect is achieved. At the same time, compared with the well killing operation, the snubbing operation has problems such as high equipment investment, complicated operation, various operation techniques, and high technical requirements for operators; the shortage of equipment includes: the pluggi...

AI Technical Summary

Problems solved by technology

At the same time, compared with the well killing operation, the snubbing operation has problems such as high equipment investment, complicated operation, various operation techniques, and high technical requirements for operators; the shortage of equipment includes: the plugging process of the plugging device takes a long time and the performance Unstable, the bridge plug rubber core can not be well adapted to different pipe diameters, etc., all of which restrict the development of snubbing operation technology in China

Existing literature has reported a large number of polymer jelly systems formed with modified starch as the main agent or gel systems with a certain strength formed with starch as a filler, but most of these jelly systems are formula compound systems. So far, there is no single report on the use of modified starch as a new material for the jelly system.