Wang Jingpeng, Xiong Youming, Lu Zongyu, Zhang Wei, Wu Jiwei, Wei Ruihua, Li Xiaoxiao
State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, Sichuan, China.
Xinjiang Oilfield Company of PetroChina, Karamay 834000, China.
ACS Omega. 2021 Oct 21;6(43):28955-28966. doi: 10.1021/acsomega.1c04009. eCollection 2021 Nov 2.
During cementing operation with oil-based drilling fluids, the casing and well wall are in the "oil wet" environment, and the cement slurry cannot achieve good cementation with the second interface, which seriously affects the cementation quality of the cementing interface. Therefore, it is very important to select a flushing fluid with good performance and high flushing efficiency for cementing operation with an oil-based drilling fluid. An integrated measurement system of interface parameters and a rotating liquid interface tension tester is selected in the room. A set of evaluation methods of wetting reversal is developed to evaluate the wetting reversal ability of type A and type-B flushing fluids on site to optimize the reasonable type and concentration of the flushing fluid. The experimental results show that under the same concentration, the surface tension and interfacial tension of type A flushing solution are lower than those of type-B; that is, the hydrophilic effect of type A flushing solution is better than that of type-B. The wettability reduction of type A is better than that of type-B. The wetting reversal ability of type A flushing solution with a surfactant concentration of 30% is better than that of type-B. The evaluation methods include surface tension, interface tension, dewetting ability, and oil washing ability of the flushing fluid, and the evaluation of the wetting reversal ability is carried out on the basis of the sandstone, sheet metal (steel for three open casings on site), and slide glass (as a reference). Then, according to the optimal concentration of the flushing fluid, a mixing experiment of the two kinds of flushing fluids is carried out to evaluate the ability of wetting reversal, and compared with the experimental results of A and B, the reasonable flushing fluid formula is finally selected. A proper analysis of the adaptability of the evaluation method of the flushing fluid is conducive to the reliable evaluation of the performance of the flushing fluid and the enhancement of the operator's ability to grasp the cementing quality. To guide the field practice has a very important practical significance, but it also has a guiding role for the development of new pre-liquid products.
在用油基钻井液进行固井作业时，套管与井壁处于“油湿”环境，水泥浆无法与第二界面实现良好胶结，严重影响固井界面的胶结质量。因此，对于用油基钻井液进行的固井作业，选择性能良好、冲洗效率高的冲洗液至关重要。在室内选用了界面参数综合测量系统和旋转液体界面张力测试仪。开发了一套润湿反转评价方法，以评估现场A、B型冲洗液的润湿反转能力，从而优化冲洗液的合理类型和浓度。实验结果表明，在相同浓度下，A型冲洗液的表面张力和界面张力低于B型；即A型冲洗液的亲水性优于B型。A型的润湿性降低效果优于B型。表面活性剂浓度为30%的A型冲洗液的润湿反转能力优于B型。评价方法包括冲洗液的表面张力、界面张力、去湿能力和洗油能力，并在砂岩、金属片（现场三开套管用钢）和载玻片（作为参照）的基础上对润湿反转能力进行评价。然后，根据冲洗液的最佳浓度，对两种冲洗液进行混合实验，评价其润湿反转能力，并与A、B的实验结果进行比较，最终选出合理的冲洗液配方。对冲洗液评价方法的适应性进行恰当分析，有利于可靠评价冲洗液性能，增强操作人员把握固井质量的能力。对指导现场实践具有十分重要的现实意义，同时对新型前置液产品的研发也具有指导作用。
