Strong-inhibition and strong-blockage aluminum-based anti-collapse water-based drilling fluid

Abstract

The invention discloses a novel aluminum-based anti-collapse agent and provides a strong-inhibition and strong-blockage aluminum-based anti-collapse water-based drilling fluid system by combining the performance requirement of drilling fluid based on the novel aluminum-based anti-collapse agent. The strong-inhibition and strong-blockage aluminum-based anti-collapse water-based drilling fluid contains the following substances in parts by weight: 100 parts of fresh water, 4 parts of sodium bentonite, 0.1-1 part of a coating inhibitor, 0.3-5 parts of a strong amine inhibitor, 0.5-5 parts of a filtrate reducer, 0.3-1 part of a thickening agent, 1-5 parts of a lubricating agent and 0.5-5 parts of an efficient aluminum-based blocking agent. The key technique of the invention is to provide use of the aluminum-based anti-collapse agent as a mud rock blocking anti-collapse agent in drilling fluid. After an aluminum-based blockage anti-collapse agent acts with a rock core with same thickness, the time required for transferring differential pressure of 1MPa is substantially shortened in comparison with the time (about 1.5 hours) required for transferring differential pressure in a blank rock core, so that the aluminum-based blockage anti-collapse agent has excellent blockage performance. Compared with the prior art, the strong-inhibition and strong-blockage aluminum-based anti-collapse water-based drilling fluid has the following advantages that (1) an amine inhibitor has prominent inhibition performance, and the hydration dispersion inhibition capacity of shale of the drilling fluid system is strong; (2) the anti-collapse agent has prominent inhibition performance and strong blockage anti-collapse capacity, and the hydration expansion inhibition capacity of shale of the drilling fluid system is strong; (3) the water-based drilling fluid system has relatively good rheological property and strong temperature resistance, salt resistance and calcium and inferior soil pollution resistance; and (4) the system contains less treating agents and is simple to prepare and convenient to maintain.

Description

technical field [0001] The invention relates to a water-based drilling fluid system in the oil drilling process. technical background [0002] Wellbore instability is a common and often encountered complex problem in oil and gas drilling. Downhole complex accidents caused by well wall instability are extremely harmful to drilling and completion, and have always been a prominent problem in the petroleum engineering circles at home and abroad. During drilling operations, once the wellbore instability occurs, it will not only delay the drilling time, damage oil and gas layers, interfere with geological logging, etc., but also lead to a series of downhole complex situations and accidents such as well collapse and drill sticking. It may even cause the wellbore to be scrapped, resulting in significant economic losses. [0003] During drilling, more than 75% of formations are shale formations, and shale instability causes more than 90% of wellbore stability problems. One of the ...

AI Technical Summary

Problems solved by technology

These systems have received good results in the field application process, but there are also shortcomings that are difficult to overcome.

For example, the use of KCl / polymer drilling fluid has environmental protection problems, and at the same time interferes with mud logging. Polymer alcohol plugging agents are expensive and difficult to use on a large scale. The biggest weakness of silicates is that rheology is difficult to control.

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