热采井抗高温长效水泥固井技术研究与现场应用

稠油油藏大多采用热力降粘的方式开采,主要是采用蒸汽热采的方法。注蒸汽热采一般为蒸汽吞吐,后期转为蒸汽驱,因此热采稠油井的固井必须适合和满足蒸汽吞吐和蒸汽驱开采方式。后期注蒸汽开采时,由于地层的保温效果很差,高温蒸汽在注入过程中能量通过水泥环很快耗散到地层中,导致稠油油藏达不到注蒸汽热采的效果,严重影响稠油油藏的开发效果。在注蒸汽开采过程中,水泥石在高温蒸汽环境中强度衰减严重,导致水泥环破裂损坏,使原本封固好的环空失效,引发油气水窜,严重缩短油井寿命。针对稠油油藏固井存在的问题,须研究开发一种适用于封固稠油热采井的长效固井技术,使该固井技术具有水泥浆热容高、保温效果好,可延缓蒸汽注入过程中能量损失;水泥浆具有良好的强胶结性能,大大改善固井第二界面胶结强度,有效防止油气水窜的发生,提高浅层水泥封固段长期封固效果;水泥石强度高,抗高温性能好,其强度在高温下衰减缓慢,可经受稠油热采高温蒸汽的侵蚀的优点。有效解决稠油热采井在高温驱替环境下固井质量差、油井寿命短的问题,为稠油油藏勘探开发提供有力的技术支撑。

The technology research and field application of resistance to high temperature and long-acting cementing

The exploitation of heavy oil reservoir mainly adopt the method of thermal recovery of steam.The way of thermal steam injection usually takes steam huff and puff,later it commonly converts to steam drive,so the thermal recovery of heavy oil well cementing must fit and meet the steam soak and steam flooding.Later when the steam injection production is going on,due to the formation of the heat preservation effect is very poor,the energy of high temperature steam disappears by cement ring to formation causes the failure of steam injection,it serious influences the effect of heavy oil reservoir development.In the process of steam injection,the cement intensity attenuation in the high temperature steam environment is in mining,it directly leads to the crack damage and the failure of cementing and causes oil and gas water channeling,serious shorten the well life.For this problem,we should develop a suitable technology for solving the heavy oil thermal recovery wells of long-acting cementing,make the cementing technology has high slurry heat capacity,the perfect effect of heat preservation,it also delay the energy loss in the process of steam injection;Improving the effect of shallow cement cementing segment long cementing with high intensity,high temperature resistant performance.The attenuation of intensity at high temperature must be slow and soft in order to bearing the erosion of high temperature steam.It will effectively solve the poor cementing quality in high temperature environment and provides strong technical support of heavy oil reservoir exploration.