Strong-inhibition and strong-cementation well wall stabilizer and preparation method thereof

Abstract

The invention relates to a strong-inhibition and strong-cementation well wall stabilizer and a preparation method thereof. The strong-inhibition and strong-cementation well wall stabilizer is characterized by containing a branched polyethyleneimine structure as a main chain and a catechol group grafted to the main chain. The strong-inhibition and strong-cementation well wall stabilizer has the beneficial effects that the strong-inhibition and strong-cementation well wall stabilizer has better well wall stabilization effect, is convenient in control on preparation process, simple to operate andstable in quality of a product and has better action effect when being used under the condition with the temperature being 150 DEG C, and a water-based drilling fluid system formed by taking strong-inhibition and strong-cementation well wall stabilizer as a key treating agent has relatively good rheological property, rejection capability and anti-sloughing property; and a drilling fluid treatingagent which can strongly inhibit hydration swelling of shales, can block consolidated rocks at the same time, improves the mechanical property of the shales and strengthens the pressure-bearing capacity of the well wall can effectively push a water-based drilling fluid to replace an oil-based drilling fluid, more efficiently keeps the well wall stablity and has an important theoretical and practical significance.

Description

technical field [0001] The invention relates to a well wall stabilizer for drilling fluid in the oil drilling process, in particular to a well wall stabilizer with strong inhibition and strong cementation and a preparation method thereof. Background technique [0002] As the country's demand for oil and gas resources continues to expand, and the number of deep wells, ultra-deep wells and shale gas wells under complex formation conditions continues to increase, the performance of drilling fluids must be able to meet more stringent requirements. Among them, the wellbore stability problem has always been a worldwide problem in the drilling process. Downhole complexities and accidents caused by wellbore instability, such as well collapse, reduced diameter sticking, and bit balling, have caused a large amount of economic losses to the petroleum industry every year. . In order to solve the problem of wellbore stability, oil-based drilling fluid and high-performance water-based dr...

AI Technical Summary

Problems solved by technology

Although oil-based drilling fluid can effectively stabilize the borehole wall, it has problems such as high cost, unfriendly to the environment, and poor cementing quality

At present, there is no water-based drilling fluid system that can completely inhibit the hydration of clay, so it cannot effectively solve the problem of wellbore instability, and cannot replace oil-based drilling fluid to meet the needs of complex geological conditions and unconventional oil and gas reservoir drilling

[0003] Studies have shown that the instability of shale wellbore is the result of multi-factor and multi-field coupling of "mechanics-chemistry". Conventional drilling fluid treatment agents often focus on chemical factors, that is, to reduce the chemical interaction between drilling fluid and formation. Ignoring the mechanical factors and the synergistic effect between force and transformation, it is difficult to achieve real wellbore stability

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