杏六区薄差储层有效动用界限研究

Study on Effective Producing Limitation of the Thin and Poor Pay Zones in Xing 6 Block

大庆长垣内部油田已进入高含水期,目前的水驱开发对象已由中高渗透层逐渐转变为薄差储层,这类储层油藏地质条件复杂,开发效益较差,已探明的储量中却有数亿吨储量主要存在于低渗透的薄差储层中.由于其微观孔隙结构和物性特征与厚油层存在差异,有些物性较差的储层甚至无法动用.以大庆油田杏六区的薄差储层为研究对象,运用压力数法和非线性渗流指数法确定有效动用的渗透率下限,利用双管并联实验确定级差上限,结合核磁共振技术与压汞实验结果给出孔喉动用的下限,得出:杏六区薄差储层有效动用的渗透率下限为1×10^(-3)μm^2;级差上限为5;流动孔喉半径下限为0.288μm,该结果为薄差储层的有效开发提供了一定的参考和借鉴.

The interior of Daqing placanticline oil field has already entered the period of high water cut,the current water flooding development objects in the high and moderate permeableness layers gradually transformed into poor thin layers,such reservoirs with the complicated structure have poor development benefits,but the remaining reserves of several million tons of the demonstrated reserves mainly exist in low permeability poor thin layers.Because its microscopic pore structure and physical characteristics are differrent from the thick reservoirs,some poor reservoir can not even producing.Taking Xing-6 Blocks of Daqing Oil Field as the research object,the lower producing limit of permeability is determined by pressure method and nonlinear flow index method,the upper contrast limit is determined based on the laboratory parallel two transistors testing,and the lower pore throat mobilization is determined based on the NMR experiments.The result show that the permeability lower producing limit of the Xing-6 Block＇s thin and poor layers is 1×l0^（-3）μm^2,the effectively producing upper contrast limit of the thin and poor layers is 5,and the mean flow pore throat radius limit is 0.288μm.