Open Access

ARTICLE

The Conversion of Non-Dispersed Polymers into Low-Potassium Anti-Collapse Drilling Fluids

by Hao Hu^1,2,3, Jian Guan⁴, Shanfa Tang^1,2,3,*, Jialuo Rong^1,2,3, Yuanpeng Cheng^1,2,3

1 School of Petroleum Engineering, Yangzte University, Wuhan, 430100, China
2 Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering, Yangtze University, Wuhan, 430100, China
3 School of Petroleum Engineering, Yangtze University, National Engineering Research Center for Oil & Gas Drilling and Completion Technology, Wuhan, 430100, China
4 Engineering Technology Research Institute of PetroChina Great Wall Drilling Engineering Co., Ltd., Panjin, 124000, China

* Corresponding Author: Shanfa Tang. Email:

Fluid Dynamics & Materials Processing 2024, 20(2), 325-335. https://doi.org/10.32604/fdmp.2023.042055

Received 30 March 2023; Accepted 14 July 2023; Issue published 14 December 2023

Abstract

Different drilling fluid systems are designed according to mineral composition, lithology and wellbore stability of different strata. In the present study, the conversion of a non-dispersed polymer drilling fluid into a low potassium anti-collapsing drilling fluid is investigated. Since the two drilling fluids belong to completely different types, the key to this conversion is represented by new inhibitors, dispersants and water-loss agents by which a non-dispersed drilling fluid can be turned into a dispersed drilling fluid while ensuring wellbore stability and reasonable rheology (carrying sand—inhibiting cuttings dispersion). In particular, the (QYZ-1) inhibitors and (FSJSS-2) dispersants are used. The former can inhibit the hydration expansion capacity of clay, reduce the dynamic shear force and weaken the viscosity; the latter can improve the sealing effect and reduce the filtrate loss. The results have shown that after adding a reasonable proportion of these substances (QYZ-1: FSJSS-2) to the non-dispersed polymer drilling fluid, while the apparent viscosity, plastic viscosity, structural viscosity and fluidity index underwent almost negligible changes, the dynamic plastic ratio increased, and the filtration loss decreased significantly, thereby indicating good compatibility. According to the tests (conducted in the Leijia area), the density was 1.293 g/cm³, and after standing for 24 h, the SF (static settlement factor) was 0.51. Moreover, the filtration loss was reduced to 4.0 mL, the rolling recovery rate reached 96.92%, with excellent plugging and anti-collapse performances.

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Keywords

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