Basfar Salem, Shokry Amir, Iqbal Arsalan, Elkatatny Salaheldin, Alajmi Shabeeb
Department of Petroleum Engineering, College of Petroleum Engineering & Geosciences, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia.
ACS Omega. 2025 Mar 9;10(10):9976-9985. doi: 10.1021/acsomega.4c07376. eCollection 2025 Mar 18.
Drilling fluid is an essential component that helps keep the wellbore stable during fast drilling operations. However, problems arise when drilling fluids are contaminated with cuttings from the drilled formation, which impacts the wellbore integrity and fluid characteristics. The effectiveness of drilling operations depends on understanding and managing this relationship correctly. This study examined the influence of kaolin clay as drilling cuttings on barite-weighted oil-based drilling fluid (OBDF). Different quantities of kaolin clay (0, 5, 10, and 15 wt %) were intentionally added as impurities to the OBDF. The evaluation included important characteristics of drilling mud post-hot rolling such as fluid density, emulsion stability, rheology, and filtration performance under high-pressure and high-temperature (HPHT) conditions. The rheological behavior exhibits a gradual change at low solid concentrations but has a rapid increase as the percentage of solids becomes higher. The addition of kaolin clay, comprising less than 10 wt %, had no discernible impact on the yield point (YP). However, 15 wt % of kaolin clay increased the YP by 81%. Furthermore, the increase in gel strength is more pronounced at 10 and 15 wt %. Additionally, plastic viscosity (PV) increased by 19, 35, and 73% when adding 5, 10, and 15 wt % of kaolin clay solids. Incorporating kaolin clay led to increases in both the thickness of the filter cake and the filtrate amount. Kaolin clay reduced the electrical stability but sustained over 400 V at various concentrations. This study emphasizes the importance of understanding formation-drilling fluid interactions for successful drilling operations. Tailoring drilling fluids to specific formations, such as controlling clay content, can ensure wellbore stability and efficient drilling.
钻井液是一种重要的成分，有助于在快速钻井作业期间保持井筒稳定。然而，当钻井液被来自钻孔地层的岩屑污染时，就会出现问题，这会影响井筒完整性和流体特性。钻井作业的有效性取决于正确理解和管理这种关系。本研究考察了高岭土作为钻井岩屑对重晶石加重油基钻井液（OBDF）的影响。故意向OBDF中添加不同数量的高岭土（0、5、10和15重量%）作为杂质。评估包括高温高压（HPHT）条件下热滚后钻井泥浆的重要特性，如流体密度、乳液稳定性、流变学和过滤性能。流变行为在低固相浓度下呈逐渐变化，但随着固相百分比的升高而迅速增加。添加含量低于10重量%的高岭土对屈服点（YP）没有明显影响。然而，15重量%的高岭土使YP增加了81%。此外，在10重量%和15重量%时，凝胶强度的增加更为明显。另外，当添加5、10和15重量%的高岭土固体时，塑性粘度（PV）分别增加了19%、35%和73%。加入高岭土导致滤饼厚度和滤液量均增加。高岭土降低了电稳定性，但在不同浓度下均保持在400 V以上。本研究强调了理解地层与钻井液相互作用对于成功钻井作业的重要性。根据特定地层调整钻井液，如控制粘土含量，可以确保井筒稳定和高效钻井。
