THAI火驱稳定燃烧的调控方法实验研究

Experimental Study on Stable Propagation Control Method of THAI Process

为了解决THAI火驱在矿场试验中空气沿水平井突进以及水平井生产管柱结焦堵塞的问题,以新疆油田A稠油油藏为研究对象,利用自主研制的三维物理模拟实验装置(耐压5 MPa、耐温600℃),研究了THAI火驱过程中燃烧区带展布情况以及稳定燃烧调控方法。结果表明:已燃区覆盖的区域具有"船头"的形貌特征,超覆燃烧明显,将已燃区控制在水平井外是稳定燃烧的关键,燃烧腔的横向扩展长度与THAI火驱动用程度相关;在THAI火驱过程中,实验采用5~7 L/min的注空气速度、生产压差控制在50~70 k Pa范围内,能够维持燃烧前缘的稳定推进。该稳定注气流量和生产压差的调控方法在新疆油田A稠油油藏火驱先导试验区取得了较好的试验效果。

In order to solve the problems of air breakthrough and production string coking and blocking in THAI（Toe-to-Heel Air Injection） process of horizontal well,taking A heavy oil reservoir in Xinjiang oilfield as the research object,the distribution of combustion zones and the control method of combustion stably propagating in THAI process are studied by using the independently developed 3D physical simulation experiment device（pressure resistance of 5 MPa,the temperature resistance of 600 ℃）. The result shows that,the shape of combusted zone is similar to a ＂ ship＇s bow＂,and there is obvious overlap combustion; the key to stable combustion is control the combusted zone outside the horizontal well,and the transverse expansion length of combustion chamber is related to the utilization degree of THAI process; in the experiment,air injection rate is 5 ~ 7 L/min,and production pressure difference controls in the range of50 ~ 70 k Pa,which can maintain the stable propagating of combustion front. The method of controlling the stable gas injection flow rate and the production pressure difference was applied in the THAI pilot test of A heavy oil reservoir of Xinjiang oilfield,and a good result was achieved.