Research on plant gum film-forming drilling fluid system for deep overburden layers based on response surface experiment

Abstract:

With the accelerating consumption of mineral resources and the introduction of the national new round of mineral prospecting breakthrouch strategy， new requirements have been put forward for exploration and prospecting in complex deep overburden layer， where the geological drilling environment is complex. Wire-line core drilling technology is widely used for drilling in the complex strata. To enhance the drilling efficiency and core recovery of wire-line coring drilling in deep overburden layers， and to maintain borehole wall stability， an environmentally friendly plant-gum film-forming drilling fluid system was developed. Through optimization tests， konjac gum was selected as the film-forming matrix. On this basis， the film-forming aid PVA， the rheology modifier HJ， and polyamine anti-sloughing inhibitor AB-1 were further identified. Based on the response surface test， the optimized formulation K-PA of the plant-based film-forming drilling fluid was obtained， that is 0.3% konjac gum + 0.9% PVA + 0.6% HJ + 1% AB-1 + 0.2% soda ash， moreover， its film-forming and anti-sloughing mechanism was analyzed. This drilling fluid system exhibits outstanding film-forming filtration reduction and hydration inhibition capabilities to achieve anti-sloughing and wall protection， showing good adaptability to deep overburden layers. The performance test results are highly consistent with the model predictions， demonstrating the high reliability of the response surface test design. The research results provide a new approach for solving complex formation problems， and also offer certain reference significance for the development of new environmentally friendly solid-free drilling fluids.