绿色环保型阻垢剂的研究与应用

为了解决下寺湾油田雨岔区块油井管杆结垢严重的问题,通过现场调研和取样化验分析,发现采出水中Ca~(2+)、Mg~(2+)、CO_3~(2-)、SO_4~(2-)等成垢离子含量较高,同时采出水中细菌含量超标,尤其是SRB菌含量高达10~3/m L。结合雨岔区块油井结垢的主要原因,室内以聚环氧琥珀酸(PESA)和聚天冬氨酸(PASP)作为主剂,优选了缓蚀剂、杀菌剂、分散剂等助剂,优选出绿色环保型阻垢剂配方,并对其缓蚀阻垢性能、生物降解性能进行了测试。现场应用结果表明,措施井平均Ca~(2+)保持率达到81.6%,平均缓蚀率达到80.6%;措施井免修期由75 d提高到247 d;该阻垢剂体系有较好的阻垢和缓蚀双重功效,能够解决下寺湾油田雨岔区块的油井结垢问题,减少油井维护性作业井次,降低油井生产成本。

Research and application of environment-friendly scale inhibitor

In order to address the problem of severe scaling in tubing and rod in oil wells on Yucha Block of Xiasiwan Oilfield, field research and sampling inspection revealed that the produced water had a high content of scaling ions like Ca2+, Mg2+, CO32– and SO42–, and also had a high content of bacteria, esp. SRB bacteria, which was up to 103/mL. In consideration of the main causes for scaling in oil wells on Yucha Block, the PESA (Polyepoxysuccinic acid) and PASP (polyaspartic acid) were used as the main agent in lab experiment and such additives as corrosion inhibitor, bactericide, dispersant, etc. were optimized, from which the environment-friendly scale inhibitor formula was chosen, and tests were made on its corrosion and scaling inhibition properties and biodegradation properties. The result of field application shows that the average retention rate of Ca2+ was up to 81.6% and the average inhibition rate was up to 80.6% in stimulated wells. The repair-free period of stimulated wells was increased from 75 d to 247 d. This scale inhibiting system has a double function of scale inhibition and corrosion inhibition, can address the scaling problem in oil wells on Yucha Block of Xiasiwan Oilfield, reduce the maintenance operations on oil wells and reduce oil well production costs.