胡尖山油田A83长7致密油加密可行性分析

Feasibility analysis of dense oil encryption of A83 Chang 7 in Hujianshan oilfield

陕北长7致密油分布范围广,储量丰富。2010年投入开发,经历了由定向井到水平井、常规压裂到体积压裂的转变。目前主要以"长水平段+体积压裂"的模式进行开发,初期单井产量达到10 t以上,由于储层致密,启动压力梯度高,常规注水开发压力传递较慢,有效驱替系统难建立,加之存在裂缝等优势渗流通道,整体表现出注水不见效、见效即见水的水驱矛盾;呈现单井产量低、采油速度低、采出程度低"三低"现状。如何提高采油速度,提高采出程度,对致密油长期有效规模开发意义重大。

Chang 7 compact oil in northern Shaanxi is widely distributed and abundant in reserves. In 2010, it went through the transformation from directional well to horizontal well,conventional fracturing to volume fracturing.At present, the development is mainly carried out in the mode of "long horizontal section + volume fracturing". In the initial stage, the production of single well reaches more than 10 t. Because of the tight reservoir, high starting pressure gradient, slow pressure transmission of conventional water injection development,difficult to establish effective displacement system, and the existence of predominant seepage channels such as fractures, the overall performance of water injection is ineffective and water flooding contradiction is effective. Low production, low oil recovery rate, low recovery degree "three low" status quo. How to improve the recovery rate and recovery degree is of great significance to the long-term and effective large-scale development of tight oil.