储层物性时变的稠油底水油藏定向井水锥变化

Influence of Time-varying Reservoir Physical Properties on Water Cone Change of Directional Wells in Heavy Oil and Bottom Water Reservoirs

针对现有稠油底水油藏定向井水锥变化公式未考虑由于长期大液量冲刷引起的储层物性变化,导致水驱波及体积偏大,剩余油认识偏悲观等问题,为了更准确地描述高含水阶段定向井水锥变化规律,以及井间剩余油分布规律,综合考虑了长期大液量冲刷下储层物性的变化规律,并运用等值渗流阻力对水锥体内外储层渗透率进行等效表征,推导了考虑物性时变性的稠油底水油藏数值变化关系式。实例分析发现,储层物性时变性对水锥的影响十分显著,相同水锥宽度下,较不考虑物性时变的水锥公式所计算的水锥高度降低了46.3%,与实钻过路井测井解释结果对比,相对误差仅为5.3%。矿场先导试验证实了考虑物性时变性的底水油藏定向井水锥变化公式的可靠性,为准确描述长期大液量冲刷下稠油底水油藏高含水阶段水锥变化及剩余油分布规律提供了技术支持。

In view of the existing water cone variation formulas of directional wells in heavy oil and bottom water reservoirs,the changes of reservoir physical properties caused by long term large fluid volume scour have not been considered,which lead to the large sweep volume of water flooding,pessimistic understanding of remaining oil and poor reserve production degree and so on.In order to describe more accurately the variation law of water cone and the distribution of remaining oil between wells in high water cut stage,the variation law of reservoir physical property under long term large fluid volume scour is considered synthetically.The equivalent percolation resistance is used to characterize the permeability of the reservoir inside and outside the water cone,and the equation of numerical variation of heavy oil and bottom water reservoir considering physical property time variation is derived.Through the analysis of practical examples,it is found that the influence of reservoir physical property time variation on water cone is very significant.Under the same water cone width,the water cone height calculated by the water cone formula,which does not take account of the time-varying physical properties,is reduced by 46.3%.Compared with the results of log interpretation,the relative error is only 5.3%.The field pilot test proves the reliability of the water cone change formula of the directional well in the bottom water reservoir considering the time variation of physical properties.This re seach provides technical support for accurate description of water cone change and residual oil distribution law of heavy oil bottom water reservoir in high water cut stage under long term large liquid volume scour.