绿泥石弱酸性解堵剂的开发与性能评价

黏土矿物常对油田储层造成污染和堵塞，绿泥石矿物是黏土矿物的主要组成部分之一。目前现场常采用的强酸性解堵剂腐蚀性大，作用时间短，当体系质子消耗到一定量时，体系解堵效率大大降低。为了解决以上问题，对各产地绿泥石物性分析比较，引入缓冲概念，针对性地复配了一种螯合能力强、具有缓冲能力的弱酸性解堵剂。通过室内实验研究发现:在解堵主剂质量浓度4%、pH值为5条件下，解堵剂对绿泥石24 h溶蚀率达25%，说明该解堵剂具有溶蚀率高、解堵效果好、腐蚀性弱以及配伍性好的优点。机理研究表明，解堵剂和缓冲体系有效组合，持续稳定提供一定浓度质子的特点是该弱酸性绿泥石解堵剂高效解堵的关键。WZ-X井在开发开采过程中，由于钻完井液侵入地层造成黏土膨胀与运移伤害，使用绿泥石解堵剂进行解除污染，作业后该井产液量由55.5 m3/d提升至98.0 m3/d。该技术的成功应用为油田解堵提供了新的方向。的方向。 

Development and Performance Evaluation of Weak Acid Plugging Removal Agent for Chlorite

Clay minerals often pollute and block oil reservoirs. Chlorite is one of the main components of clay minerals. The strong acid as plugging remover in feature of high corrosivity and high efficiency was commonly used in the oilfields. When the protons are consumed, the efficiency of the plugging remover system is greatly reduced. To solve the problem of oilfield blockage material, this paper compares the physical properties of chlorite from various producing areas, and purposefully develops a weak acid plugging remover with a strong chelating ability to metal in clay minerals and buffering ability. The experimental research displays that under the conditions of 4% mass concentration of main plugging removal agent and pH = 5, the dissolution rate of chlorite reaches 25% under 24 h, indicating that the plugging remover has the advantages of high dissolution rate, good plugging removal effect, weak corrosion, and good compatibility. The mechanism study shows that the effective combination of plugging remover and buffer system to continuously and stably provide a certain concentration of protons is the key to the efficient plugging removal of chlorite under weak acidic conditions. During the exploitation of well WZ-X, clay swelling and migration damage were caused by drilling and completion fluid immersion into the formation. Chlorite plugging agent was used to remove pollution. After the operation, the fluid production of the well increased from 55.5 m3/d to 98 m3/d. The successful application of this technology provides a new direction for oilfield plugging removal.