管窜影响下的复杂碳酸盐岩油藏产水特征分析

Analysis of Water Production Characteristics in Complicated Carbonate Reservoir Based on Casing Channeling

针对伊拉克Ahdeb油田下白垩统复杂碳酸盐岩油藏因套管外窜流、高渗条带及多层合采等因素造成出水情况复杂,含水上升率较高的问题,建立了精细复杂碳酸盐岩油藏精细模型。在此基础上,采用实际典型产水曲线标定数模曲线的方式,结合无因次时间得到不同管窜情况下(水泥环与储层间的第二界面破损位置位于纯水层、油水过渡带和纯油层)的套管外窜流&底水锥进和纯套管外窜流的产水特征曲线。根据建立的产水特征曲线对油藏出水类型和机理进行了识别与分析。结果表明:产水特征曲线能够有效判明油藏出水类型,避免过多进行井下PLT测试等工作;出水机理分析与现场先导试验结果一致,研究结果为油藏稳油控水提供了可靠的措施对策依据。

In view of the complex type of water-producing and situation about faster rate of water cut increasing in lower cretaceous multi-layered carbonate reservoir of Ahedb field in Iraq including casing channeling,high permeability zone and commingled production,a fine reservoir model which can characterize lower cretaceous multi-layered carbonate reservoir had be built.On this basis,various simulation curves would be calibrated by the actual typical production curves to obtain the different typical water production curve including casing channeling with bottom aquifer coning and single casing channeling(including different position of casing channeling:pure water zone、oil-water transition zone and pure oil zone)with dimensionless time,which would be used to distinguish and analyze reservoir water-producing type and mechanism.The results showed that,the typical water production curve could accurately discern water production type to avoid too much downhole PLT and other tests,meanwhile,the validity of mechanism analysis has been proved by Pilot test,which can provide reliable basis for stabilizing oil and controlling water of vertical wells.