基于沉积模式约束的水平井单砂体构型技术

Single-Sand Configuration Technology of Horizontal Wells Based on Depositional Models Constraints

L10井区是塔里木油田开发最早的井区之一,目前TI油组已进入中高含水期,沉积体系复杂,沉积相变化快。油藏开发中井网不规则、密度小,砂体精细刻画难度大。前期仅依靠直井进行砂体构型研究的成果已不能满足剩余油精细挖潜需求。为此,将地震、岩心、测井、生产动态等资料进行结合,厘清TI油组为曲流河、辫状河三角洲前缘沉积;曲流河沉积的侧向加积作用导致点坝中心与两侧废弃河道间砂体发育呈“凸”字形态,三角洲前缘沉积的垂向加积作用导致河道砂体呈透镜体状,以不同沉积模式下砂体的发育特征为约束,开展直井-水平井联动单砂体构型解剖,明确单砂体纵向叠置关系、横向展布特征,精准预测剩余油分布。水平井单砂体构型技术为老油田措施挖潜提供了详实依据和支撑,为国内高效开发同类油藏提供借鉴。

As one of the earliest development areas in Tarim oilfield,the TI oil group in L10 well area has entered the middle and high water cut stage.The sedimentary system is complex,and the reservoir sedimentary facies change quickly.In reservoir development,the well pattern is irregular and the density is small,so it is difficult to accurately characterize the sand body.Early studies of sand body configuration can't meet the demand of tapping the potential of remaining oil by only using vertical wells.In this paper,the data of seismic,core,logging,production dynamics are combined to clarify the sedimentary model of TI oil group as meandering river and braided river delta frontdeposit.The lateral accretion of meandering river deposits leads to the “convex” shape of sand body development between the center of point bar and the abandoned channels on both sides.The vertical accretion of delta front deposits leads to the development of channel sand bodies in the form of lenticles.According to the development characteristics of sand bodies under different sedimentary models,the configuration of single sand body in vertical and horizontal well linkage is analyzed.The longitudinal superposition relationship and transverse distribution characteristics of single sand body are defined,and on this basis the remaining oil distribution is accurately predicted.The single sand body configuration technology of horizontal well provides detailed basis and support for tapping the potential of old oilfields,and provides reference for the efficient development of similar reservoirs in China.