水平井压裂选井选层技术探讨

Research on selection of well and formation for horizontal well fracturing

压裂水平井的开发效果和经济效益均优于压裂垂直井,横向裂缝水平井的生产效果好于纵向裂缝水平井,而水平井压裂选井选层是决定压裂效果的关键环节,成功的选井选层可提高压裂成功率和有效率,产生更高的经济效益。不同类型储层的压裂选井选层影响因素也不同,砂泥岩地层压裂的主要影响因素是储层物性、电性、含油气性和岩性,而碳酸盐岩地层压裂的主要影响因素是缝洞储集体的发育情况。探井和开发生产井的选井选层影响因素也不同,探井主要考虑地质静态参数,而开发生产井则侧重于生产动态数据。压裂选井选层人工智能系统能够根据目标区块已有的压裂数据,建立压裂效果的各类预测模型,运用这些模型实现对目标区块目的井(层)的压裂效果预测,从而达到智能化选井选层的目的。文中通过对地层不整合油藏、屋脊断块油藏、厚层底水块状油藏、缝洞型碳酸盐岩油藏及低渗透油气藏等不同类型油气藏水平井压裂选井选层影响因素的分析,提出各自的选井原则和思路,为不同类型油气藏水平井压裂选井选层提供了依据。

Development eftect and economic benefit of horizontal well fracturing are superior to the vertical well. The fractured effect of horizontal well with transverse cracks is superior to the effect of longitudinal fissure. Selection of well and formation is a key link in horizontal well fracturing. Successful selection of well and formation not only raises the fracturing returns-ratio and efficacyratio, but also creates the high economic benefit. The influence factors of selecting wells or zones to be fractured are different for different types of reservoir. The main influence factors are its physical properties, electric properties, status of hydrocarbon bearing and lithology in sand-shale reservoir fracturing, and the main influence factor is development status of fissures and caves in reservoir rock in carbonate reservoir fracturing. The main influence factors of selecting wells or zones to be fractured are different for exploration well and development well. The main factors are geological static parameters for exploration well, but dynamic performance data are considered for development well. The artificial intelligence system suitable for selecting well and zone to be fractured can set up all kinds of forecast models on fracturing effect in terms of the existing fracture data in target block. Prediction of fracturing effect can be achieved for the well （layer） of target area to attain the goal of intellectualization selecting well or zone to be fractured by using these models. The influential factors for the selection of well and target zone in horizontal well fracturing are researched in this paper for disconformity reservoir, ridge fault block reservoir, thick-bedded block reservoir with bottom water, fractured-vuggy carbonate reservoir and tight reservoir. The rule and thinking of well selection are proposed to provide a reference for the horizontal well fracturing of all types of reservoirs.