A kind of self-lubricating liquid branched polymer cutting agent and its preparation method and oil-based drilling fluid

Abstract

The invention relates to a self-lubricating liquid branched polymer cutting agent in the field of oil-based drilling fluid in petroleum drilling, a preparation method thereof and an oil-based drilling fluid. The self-lubricating liquid branched polymer cutting agent is prepared from raw materials comprising the following components through a two-step reaction: Class A substance: X i -R 1 ‑X’ j ; Wherein, X is a carboxylate group, X' is a carboxylic acid anhydride; i, j are all ≥ 0, and the total number of acid groups x=i+2j ≥ 2; Class B substances: Y m -R 2 -Y' n ; where Y is ‑NH 2 group or -NH group, Y' is an alcoholic hydroxyl group or a phenolic hydroxyl group, m and n are both ≥ 1, and the total number of basic groups y=m+n≥2; and, i+2j+m+n≥5; R 1 and R 2 All are linear, branched or cyclic aliphatic or aromatic alkyl groups, with carbon numbers in the range of 1 to 72; the branched polymer of the present invention has good self-lubricating and low-viscosity effects, and can improve oil The overall structural strength of the base drilling fluid system, the reduction of the amount of organic soil and the tolerance of the oil-based drilling fluid system to low-density solid phases solve the problem of rheological adjustment and Wellbore cleaning technical problems.

Description

technical field

[0001] The invention relates to the field of oil-based drilling fluid in petroleum drilling, and more particularly, relates to a self-lubricating liquid branched polymer cutting agent, a preparation method thereof and an oil-based drilling fluid. Background technique

[0002] In recent years, oil-based drilling fluids have been widely used in shale gas exploration and development because of their strong inhibitory properties, outstanding lubricating properties, and stability of wellbore walls. Oil-based drilling fluid is a multi-component system formed by using oil as the continuous phase, brine as the dispersed phase, and adding organic soil and weighting materials. Due to the characteristics of the system itself, oil-based drilling fluids generally have problems such as low structural force and poor suspension stability, which make it difficult to meet the rock-carrying and sand-carrying requirements of shale gas wells in extended displacement and horizonta...

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