热采水平井复合调剖技术研究与应用

Research and Application of Compound Profile Modification Technique in Thermal Recovery Horizontal Well

曙光油田D块热采水平井采出程度高,地下亏空大,地层能量不足,而且水平段动用不均情况严重,导致吞吐效果变差。目前针对热采水平井的增产措施作用单一,局限性大,不能同时解决上述两个问题,为此创新研究出复合调剖技术。复合调剖技术需要既能耐长时间高温,又不存在固相颗粒堵塞水平井筛管的调剖剂,由此研发了一种新型无固相高温凝胶调剖剂。为了解决新型无固相调剖剂封堵强度低、不耐高温的问题,引入了有机交联剂(酚醛树脂)和热稳定剂,成功提高了调剖剂封堵强度,并使调剖剂耐温指标达到了250℃左右。另外还引入了缓成胶剂(草酸),使得更多的药剂进入高动用层封堵高渗层。复合调剖技术通过向油井同时注入二氧化碳、新型调剖剂及表面活性剂,将补充地层能量与调整水平段动用相结合。复合调剖技术在D块已实施62井次,有效52井次,阶段有效率83.9%,平均单井注汽油压上升0.9MPa,平均单井增油563t,油汽比提高0.03。

The CSS production performance of D block in Shuguang oilfield was getting worse because of the high recovery percentage,lower formation energy and pressure,and serious uneven production section of thermal recovery horizontal well.Currently the role of stimulation for the thermal recovery horizontal well is single and limited to be difficult to solve these two problems above at the same time.Therefore,compound profile modification technique was researched.A new type gel was developed.In order to solve the problem of low of profile modifier with non-solid high temperature sealing intensity and poor high temperature resistance of the new agent,organic crosslinker （phenol-formaldehyde resin） and thermal stabilizer were added.After that, the sealing intensity was improved and the property was still good at about 250℃.Gel former inhibitor （oxalic acid） was added too,which made more agents enter into high-produced layers to seal the high-permeability layers.After carbon dioxide ,new type of profile modifier and surfactant were injected into the oil wells at the same time ,formation energy was supplied and horizontal section of the wells was adjusted together.The com- pound profile modification technique has been applied in D block for 62 well-times.Fifty-two well-times were effective with 83.9% of the stage effective rate.Average oil pressure of single-well steam injection in- creased by 0.9MPa,average per-well oil production increased by 563t and oil-steam ratio enhanced by 0.03.