一种具有缝洞驻留能力的堵水剂研究与评价

DEVELOPMENT AND EVALUATION OF A KIND OF WATER-BLOCKING AGENT

哈拉哈塘油田某区块为缝洞型碳酸盐岩油藏,随着开发时间的延长,高含水井逐年增加,由于油井漏失严重、堵水风险高,为此研究出了一种具有缝洞驻留能力、固化时间可调的耐温耐盐堵水剂。运用水泥稠度凝结时间测试仪、针入度测试法、岩心驱替试验、模拟缝洞装置等研究与评价方法,实验结果表明,堵水剂配方中凝结载体浓度10%,固结材料浓度4%,交联体浓度0.4%情况下针入深度仅为2 mm;对三种不同渗透率的岩心封堵率均达到90%以上;对0.8~3.7 mm缝洞的驻留能力为5 kPa/cm,3.5~7.3 mm缝洞的驻留能力为3 kPa/cm,得出了堵水剂具有强度高、封堵性能好、驻留能力强的特点,可满足该区块缝洞型碳酸盐岩油藏堵水需求。提出了先堵漏后堵水、针对不同储集层类型对堵水剂进行浓度调整等现场施工注意事项,为下步堵水实施成功提供了重要技术支撑,对同类油藏堵水具有一定的借鉴意义。

A block at Halahatang Oilfield belongs to carbonate fracture-cave reservoirs. High water cut wells have been increasing with the development proceeds. Water blocking there is highly risky because of the serious loss in those oil wells. A kind of high temperature and salt resistant water-blocking agent was developed,able to reside in the caverns or fractures and its curing time is adjustable. The experiments and evaluation by cement consistency setting time tester,needle penetration test,core flooding test and simulation seam device were used.The experimental results showed that when the concentration of condensate carrier was 10%,the concentration of consolidated material was 4% and the combined concentration was 0. 4%,the plugging depth was only 2 mm. The plugging rate was over 90%for the three cores with different permeability. The residing capacity in the 0. 8-3. 7 mm caverns or fractures was 5 KPa/cm and was 3 KPa/cm in the 3. 5-7. 3 mm caverns or fractures. The plugging agent has the characteristics of high strength,good plugging performance and high residing ability,which can be used for water blocking in the carbonate fracture-cavern reservoirs. Operation concerns are put forward herein,such as to control the well loss before water blocking,to adjust the concentration of the plugging agent for different reservoir types,etc. It provides an important technical support for the successful future water blocking and a reference for similar reservoirs.