大庆徐家围子不同储层改造的干热岩潜力评估

针对如何评估大庆徐家围子不同储层干热岩开采潜力的问题,基于徐家围子深井的地质和测井资料,对其深部存在的三种储层情况进行了划分。首先提出了各储层改造方案并建立了三维压裂模型;然后基于储层改造结果,采用水热耦合软件TOUGH2对其进行了换热分析;最终得出了不同储层的干热岩开采潜力。研究结果显示,徐家围子营城组储层是该区目前最适合进行干热岩开采的储层:根据天然裂隙发育程度,可以分为致密储层和天然裂隙发育储层,天然裂隙储层经清水剪切压裂后,采用三垂直井开采模式,最大注入速率30 kg/s,20 a产热量达17000~18500 kJ/s;根据地应力遮挡情况,可以分为遮挡层和无遮挡层,遮挡层和无遮挡层采用传统支撑剂型压裂后,采用三水平井(水平段2000 m)的开采模式,最大注入速率分别为20和32 kg/s,20 a的产热量分别为3500~5350 kJ/s和5600~7760 kJ/s。此外,虽然致密层产出热量远低于天然裂隙发育储层,但传统支撑剂型压裂和水平井技术结合后,致密储层也具有了开采干热岩的潜力。

Evaluation of Hot Dry Rock Resource Potential Under Different Reservoir Conditions in Xujiaweizi Area,Daqing

To evaluate the hot dry rock (HDR) resource under different conditions in Xujiaweizi area in Daqing ,based on the real logging data of one deep well we divided the existing conditions into several types .For each formation type , we proposed the corresponding fracturing strategy and created 3D fracturing model .Based on the stimulated reservoir ,the hydro‐thermal simulations were performed by using TOUGH2 ,and the extracted thermal energy was evaluated .The results indicate that Yingcheng formation is the most suitable reservoir for HDR development at present ;the target formation based on feature fracture could be divided into tight and fractured formation ;based on stress confinement condition ,it could be subdivided to confined and unconfined formation ;after 20 years operation (horizontal part length is 2 000 m) ,the heat production from the confined and unconfined formation are 3 500 5 350 kJ/s and 5 600 7 760 kJ/s respectively ,when the injection rate are 20 and 32 kg/s respectively ;w hereas the heat from naturally fractured formation is much higher than that from tight formation (injection rate is 30 kg/s ,heat production is 17 000 18 500 kJ/s) .Above all ,the horizontal technique makes the tight formation also have the HDR resource development potential .