High-performance water-based drilling fluid formulation

Abstract

The invention discloses a high-performance water-based drilling fluid. The high-performance water-based drilling fluid is prepared from the following components in parts by weight: 100 parts of freshwater, 2 to 6 parts of bentonite, 0.2 to 0.6 part of coating agent, 0 to 5 parts of fluid loss agents, 1 to 6 parts of lubricating fluid loss agents, 0 to 4 parts of lubricant, 2 to 6 parts of anti-collapse blocking agent, 6 to 8 parts of shale inhibitor, 0.2 to 0.4 part of pH adjusting agent, and 60 parts of weighting agents; the lubricating fluid loss agents are boric acid ester modified graphene oxide, a high-performance water-based drilling fluid system provided by the invention has the characteristics of strong inhibition, strong plugging and the like, and at the same time has the advantages of low lubrication coefficient and small downhole friction resistance, thus being suitable for construction operations of directional wells and large displacement wells.

Description

technical field [0001] The invention belongs to the technical field of drilling fluid for oil drilling, in particular to a high-performance water-based drilling fluid. Background technique [0002] With the rapid development of my country's social economy, the demand for energy is getting higher and higher. In the exploration and development of oil and natural gas and other energy resources, complex structure wells such as extended-reach wells and unconventional oil and gas long horizontal wells have gradually become the main source of improving the effect of oil and gas resources. The number of drilling methods is increasing, and the contradiction between the inhibiting lubricity of drilling fluids and the complex accidents in the well is becoming more and more prominent. Oil-based drilling fluid has the advantages of good thermal stability, good inhibition, good for wellbore stability and good lubricity, but its poor environmental acceptability and high cost limit its appli...

AI Technical Summary

Problems solved by technology

Since the wellbore stability is affected by factors such as formation rock strength, stress state of the surrounding rock, wellbore trajectory, and in-situ stress orientation, the wellbore stability of extended-reach wells is more prominent than that of conventional wells, and the inhibition of drilling fluid Higher requirements are put forward for the plugging performance, and the instability of the well wall can easily lead to block loss, increase friction, and even cause downhole accidents

In addition, it is difficult to clean the borehole of the extended-reach well, and the cuttings are not easy to be carried back to the surface in time, and the cuttings bed is easily formed, which increases the torque and friction during drilling and tripping, reduces the drilling speed, and easily leads to jamming drilling accident

As the horizontal displacement increases, most of the drilling tools lie on the bottom of the wellbore, and the contact area between the drill string and the well wall is large, resulting in a large friction resistance. In severe cases, the drilling pressure cannot be added to the drill bit

At present, the lubricant used for water-based drilling fluid has no obvious effect when dealing with highly deviated wells and horizontal wells with long horizontal sections.

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