青海跃东油田E_3~1油藏重复压裂技术现场试验

SITE TESTING RESEARCH OF RE-FRACTURING TECH- NOLOGY IN THE E_3~1 RESERVOIR FOR QlNGHAI YUE-DONG

青海跃东油田E_3~1油藏属特低渗、低孔、异常高温高压储层,单井大多依靠增产措施获得稳定产能。但储层具有杨氏模量高、易水敏及酸敏等特征。以往压裂技术也有规模小、砂比低、最大加砂浓度低、增产有效期短等不足。针对该油藏特征及以往压裂技术存在的问题,开展了重复压裂现场试验研究,现场试验6井次,施工有效率100％,最大加砂量达30.5m^3,最大砂比达46％,提高了该油藏的压裂技术水平,取得了显著效果。如YD1井增产有效期超过500d,累计增产原油3259t;YD3井压裂有效期超过600d,累计增产原油3648t。

The E31 reservoir of Qinghai Yuedong Oilfield belongs to the formation of super low permeability, porosity and anor-mal high temperature-high pressure, and most of the wells in the reservoir can achieve a stable productivity by using the stimulation technique. However, the reservoir has the characteristics of high Yong's Modulus, water-sensitivity and acid-sensitivity; and the previous fracturing techniques have many disadvantages such as the small scale, low proppant concentration, and short effective stimulation producing period etc. According to the reservoir characteristics and the problems existed in the previous fracturing techniques, the research of re-fracturing site testing has been developed, and the testing has been carried out for 6 times of wells, with success percentage of 100% . The maximum proppant volume has reached 30.5 m , and the concentration is as high as 46 %, improving the fracturing technique in this reservoir and achieving the obvious stimulation effect. Take example, the effective stimulation period of YD1 well has exceeded the 500d, the accumulated oil increase has reached 3259t; and the effective stimulation period of YD3 well has exceeded the 600d, the accumulated oil increase has reached 3648t.