Zhou Guowei, Qiu Zhengsong, Zhong Hanyi, Zhao Xin, Kong Xiangzheng
Key Laboratory of Unconventional Oil & Gas Development, Ministry of Education, China University of Petroleum (East China), Qingdao 266580, China.
College of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, China.
ACS Omega. 2021 Jan 6;6(2):1436-1444. doi: 10.1021/acsomega.0c05108. eCollection 2021 Jan 19.
The development of offshore oil and gas requires environmental protection during the drilling process. However, the existing drilling fluid additives cannot form an efficient environmentally friendly drilling fluid system. At the same time, some environmentally friendly drilling fluid additives cannot be widely used due to their high cost and complicated production process. In this paper, a natural material named wild jujube pit powder (WJPP) was used to improve the performance of the drilling fluid for the first time. The viscosity, shear force, shear thinning, rheology, filtration loss, and lubrication properties of the drilling fluid are discussed. By means of microstructure analysis, infrared spectroscopy, thermogravimetric analysis, and particle size analysis, the properties of WJPP and the drilling fluid system containing WJPP (i.e., rheological property, lubrication property, and filtration loss property) were studied. The results show that the microscopic appearance of WJPP was spherical, fibrous, block, and flake, the thermal decomposition temperature was 273.9 °C, and the suspension of WJPP was slightly acidic. WJPP can increase the viscosity, reduce the filtration loss, enhance the shear thinning and thixotropy, and reduce the lubrication coefficient of the drilling fluid. With the decrease in the particle size of WJPP, the shear thinning and thixotropy of the drilling fluid are enhanced, the viscosity and shear force increased, and the filtration loss and lubrication coefficient decreased. With the increase in the dosage, the shear thinning of the drilling fluid was enhanced, the filtration loss and coefficient of friction decreased, the viscosity and shear force increased, while the thixotropy did not change significantly. The microstructure test of mud cake showed that WJPP could form a grid structure. Combined with the blocking action of particles, the structure could prevent water molecules from passing through to reduce the filtration loss. WJPP can improve the rheological property, filtration property, and friction property of the drilling fluid, which has certain application prospects.
海上油气开发需要在钻井过程中进行环境保护。然而，现有的钻井液添加剂无法形成高效的环保钻井液体系。同时，一些环保钻井液添加剂由于成本高、生产工艺复杂而无法广泛应用。本文首次使用一种名为酸枣核粉（WJPP）的天然材料来改善钻井液性能。讨论了钻井液的粘度、剪切力、剪切稀释性、流变学、滤失量和润滑性能。通过微观结构分析、红外光谱、热重分析和粒度分析，研究了WJPP以及含WJPP的钻井液体系（即流变性能、润滑性能和滤失性能）的性质。结果表明，WJPP的微观形貌为球形、纤维状、块状和片状，热分解温度为273.9℃，WJPP悬浮液呈弱酸性。WJPP可以提高钻井液的粘度，降低滤失量，增强剪切稀释性和触变性，并降低钻井液的润滑系数。随着WJPP粒径的减小，钻井液的剪切稀释性和触变性增强，粘度和剪切力增大，滤失量和润滑系数降低。随着加量的增加，钻井液的剪切稀释性增强，滤失量和摩擦系数降低，粘度和剪切力增大，而触变性变化不明显。泥饼微观结构测试表明，WJPP可以形成网格结构。结合颗粒的封堵作用，该结构可以阻止水分子通过以降低滤失量。WJPP可以改善钻井液的流变性能、过滤性能和摩擦性能，具有一定的应用前景。
