Drilling fluid and preparation method thereof

Abstract

The invention discloses a drilling fluid and a preparation method thereof. The drilling fluid comprises Nml of water, wherein N is a positive number, 0.002N-0.005N gram of anhydrous sodium carbonate Na2CO3, 0.04N gram of bentonite for the drilling fluid, 0.003N-0.006N gram of coating agent, 0.015N-0.02N gram of tackifier, 0.01N-0.02N gram of filtrate reducer, 0.015N-0.03N gram of anti-collapse agent, 0.02N-0.03N gram of lubricant, 0.01N-0.015N gram of dispersing agent, 0.05N-0.08N gram of rigid bridging agent and 0.08N-0.15N gram of rigid filler. The drilling fluid of the invention is applicable to a loss formation and has obvious leakage stoppage effect, a leak-proof function at the same time and obvious inhibiting effect on a formation which is easy to disperse and collapse.

Description

technical field [0001] The invention relates to the technical field of oil and gas field drilling in the petroleum industry, in particular to a drilling fluid and a preparation method thereof. Background technique [0002] Borehole wall instability is a major problem that is common in the oil drilling process and has been plaguing the oil industry. Well wall instability includes: well wall collapse, lost circulation, etc. According to a conservative estimate, wellbore instability will cause losses of US$500-600 million to the world oil industry every year. [0003] Since the drilling project is an underground project involving complex and ever-changing geological structures, the wellbore instability caused during the construction will also induce other downhole accidents. The important content of unremitting efforts to tackle key problems. [0004] For a long time, Chinese petroleum workers have often encountered the problem of wellbore instability during drilling. Espec...

AI Technical Summary

Problems solved by technology

[0006] (1) Applicable to a single formation

One type of drilling fluid is only suitable for one type of formation, such as sandstone formation, mud shale formation or salt gypsum formation, etc., and does not have a broad spectrum, that is, it is not suitable for various lithological formations;

[0007] (2) Single anti-collapse performance

It only has the anti-collapse effect on the easily dispersed or only on the easily collapsed strata, and does not have the simultaneous anti-collapse effect on the easily dispersed and easily collapsed strata;

[0008] (3) single function

[0009] In summary, the existing drilling fluids have single performance and cannot effectively prevent wellbore instability

Images