双水平井SAGD循环预热传热计算及影响因素分析

双水平井SAGD开采正式生产之前需要对上下平行的注采井对之间的油层进行预热，预热效果对SAGD的成功开发至关重要。通过建立双水平井SAGD循环预热的计算模型，以风城油田SAGD水平井为例，模拟计算了循环预热过程中的相关参数，研究了水平井对之间的空间距离、蒸汽循环的速度以及循环蒸汽的干度对预热效果的影响。分析认为，循环预热蒸汽干度为0.8时，蒸汽循环速度应不低于30 t/d；若以较高的速度60 t/d循环预热时，蒸汽干度不宜低于0.4. 水平井对距离为5 m时，循环预热时间约为93d

Heat Transfer Calculation and Influence Factors Analysis for SAGD Circulation Phase in Dual Horizontal Wells

Before bringing into production of dual horizontal wells by steam assisted gravity drainage (SAGD) process, the reservoir preheating between up an down parallel injection?production well pair is required. The preheating effectiveness is very important to the successful development by the SAGD process. In this paper, the calculation models for circulation preheating of dual horizontal wells by SAGD are developed. Taking one SAGD well pair in Fengcheng oilfield as an example, the relevant parameters during the preheating phase are simulated and calculated, including studies of the effects of distance between the two wells, the speed of steam circulation and the steam quality on the preheating effectiveness. The analysis indicates that when the steam quality in the phase of circulation preheating is 0.8, the speed of steam circulation should not be less than 30 t/d; while the speed reaches 60 t/d, the steam quality should not be less than 0.4; the distancebetween the horizontal well pair is about 5 m, the time of circulation preheating is about 93 days