耐240 ℃超高温高密度钻井液探索性实验研究

Exploratory research on high-density drilling fluids with 240℃ ultra-high temperature resistance

摘要:

随着深部油气、高温干热岩勘探与深地探测战略实施，钻井液长期处于高温高压恶劣环境，超高温高压下水基钻井液性能稳定性是超高温井钻探的一项关键技术。分析了超高温科学钻探工程钻井液面临的技术难题，提出了耐240 ℃超高温高密度水基钻井液配方的设计思路。采用单因素法，优选了耐240 ℃超高温高密度水基钻井液用关键处理剂。利用不同高温处理剂的协同增效作用，初步研发了一套抗温240 ℃、密度2.0 g/cm³的超高温高密度水基钻井液配方。研究结果表明，经240 ℃老化16 h后，最优配方的钻井液具有良好的流变性和降滤失性能，其表观粘度变化率<30%，180 ℃高温高压滤失量≤24 mL。

Abstract:

With the implementation of deep oil and gas exploration， high temperature hot dry rock exploration and deep earth exploration strategy， the drilling fluids have been in high temperature and high-pressure environment for a long time， and the stability of water-based drilling fluids under ultra-high temperature and high pressure is a key technology for ultra-high temperature well drilling. In this paper， the technical problems faced by drilling fluids in ultra-high temperature scientific drilling engineering are analyzed， and the design approach for high density water-based drilling fluids formula resistant to 240℃ ultra-high temperature are proposed. The key additives for 240℃ ultra-high temperature and high density water-based drilling fluids were selected by single factor method. Using the synergistic effect of different high temperature additives， a set of ultra-high temperature and high density water-based drilling fluid formula with temperature resistance of 240℃ and density of 2.0g/cm³ was preliminarily developed. The results show that after aging at 240℃ for 16h， the optimal formulation of drilling fluids have good rheology and filtration reduction performance. Its apparent viscosity change rate is less than 30%， and the filtration loss at 180℃ is less than 24mL.