摘要
在钻遇断层、溶洞、恶性裂缝时,有很大概率发生失返性漏失,导致钻井液大量漏入地层,既损害环境,又大大增加钻井成本。对此类恶性漏失的封堵,凝胶堵漏是一个好的选择,要实现较好的封堵效果,对凝胶的各项物理性能有一定要求,目前大多数凝胶多用于水基钻井液堵漏,对油基钻井液的抗侵污能力较差。因此,室内开发了一套堵漏凝胶体系,对凝胶体系的稠化时间、凝胶强度、抗侵污能力进行了评价,并进行了模拟堵漏评价。结果表明,凝胶的强度可达20 N,强度远大于多数堵漏用水凝胶;pH值为10左右,满足入井流体的pH值条件;凝胶的成胶时间可控制在2~4 h,提供了足够的安全施工时间;在油基钻井液浸污达到30%的条件下依然可以形成凝胶,有较好的抗侵污能力。凝胶体系的各项性能指标表明其可用于裂缝及溶洞等恶性漏失的堵漏。现场应用了2口井,均体现出较好的封堵效果。
When drilling into faults,karst caves and severe fractures,there is a high probability of mud loss without return,resulting in a large amount of drilling fluid lost into the formation,which damages the environment and greatly increases drilling costs.Gel plugging is a good choice for this kind of severe lost circulation.To achieve a better plugging effect,the certain physical properties of the gel are required.At present,most gel are usually used for water-based drilling fluid plugging with poor antifouling ability to oil-based drilling fluid.Therefore,a plugging gel system was developed in the laboratory,and its gelation time,gel strength and antifouling ability of the gel system were evaluated,and a simulated plugging evaluation was carried out.The results show that the gel strength can reach 20 N,which is much stronger than that of most plugging hydrogel;the pH value is about 10,which meets the pH conditions of the fluid entering the well;the gelation time of the gel can be controlled within 2-4 hours,providing enough time for safe operation.Under the condition that the oil-based mud intrusion reaches 30%,the gel can still be formed,and it has good anti-fouling ability.The performance indicators show that the gel system that can be used to fractures and karst caves plugging.It has been applied in two wells on site,both of which show good plugging effect.
作者
李炎军
张万栋
吴江
张振祖
黄晓
许明标
陈侃
LI Yanjun;ZHANG Wandong;WU Jiang;ZHANG Zhengzu;HUANG Xiao;XU Mingbiao;CHEN Kan(CNOOC(China)Co.,Ltd.Zhanjiang Branch,Zhanjiang,Guangdong 524057,China;Huangqing Oil Production Plant,PetroChina Yumen Oilfield Company,Qingyang,Gansu 745000,China;Yangtze University,Jingzhou,Hubei 434023,China;Cooperative Innovation Center of Unconventional Oil and Gas,Wuhan,Hubei 430100,China)
出处
《钻采工艺》
CAS
北大核心
2023年第3期154-158,共5页
Drilling & Production Technology
基金
国家重大科技专项“莺琼盆地高温高压天然气富集规律与勘探开发关键技术”(编号:2016ZX05024-005)
中海石油(中国)有限公司重大科技专项“莺琼盆地高温高压钻完井液、固井工艺研究与应用”(编号CNOOC-KJ 135 ZDXM 24 LTD ZJ02)联合资助。
关键词
钻井漏失
油基钻井液
堵漏
恶性漏失
氢键凝胶
drilling fluid loss
oil-based drilling fluid
plugging
severe loss
hydrogen bonded gel
