南七—杏一区东部一类油层聚驱合理压力界限研究

发布时间：2018-04-24 20:20

  本文选题：一类油层 + 聚驱　； 参考：《东北石油大学》2017年硕士论文

【摘要】：南七-杏一区东部一类油层地区葡Ⅰ组河道砂体规模变小、储层条件变差,水驱阶段综合含水、采出程度及水淹厚度比例高。注聚以来存在三方面问题:一是见效慢,见效不均衡,见效比例低;二是粘损高,高回压高沉没度井比例大;三是部分井区压力梯度低,流压水平高,不利用扩大波及体积,影响区块聚驱开发效果。由于注采压力梯度与聚驱开发效果紧密相关,如何构建一个合理的聚驱压力梯度,显得尤为重要。本文为搞清聚驱开发过程中地层压力影响因素及变化特征,建立精细三维地质模型,应用数值模拟软件开展历史拟合,研究地层压力与聚合物溶液浓粘度、注入强度、注入速度、注采比、采出井流压、沉没度、采液强度等多参数之间关系,并归纳总结不同阶段地层压力变化特征,最后建立地层压力预测模型。同时研究了不同驱替阶段油井流入动态的数学模型,建立不同阶段合理的流压界限。聚合物驱油井流入动态是分析油井生产状态的基础,是合理设计举升方式及生产制度的关键。在聚合物驱油过程中,含聚合物的油井产出液表现出明显的非牛顿特性,因剪切、降解等作用,使得地层流体的流变性发生较大变化。因此,常规的水驱油井流入动态模型不能用于确定该类井的流入动态关系。国内外关于聚合物驱机采井合理流压的研究较少,聚驱采出液呈现拟塑性,流体性质受含聚浓度、含水率影响较大,结合聚合物驱不同阶段流体的流变特性,在保证油井产量最大化的前提下,研究高、低流压对提高采收率的影响程度,从而确定出不同阶段最佳合理流压界限。注聚初期4.5~6MPa,含水下降期3.4~4.5MPa,含水回升期4~5.5MPa。通过研究分类井组注采参数与注采压差之间的关系,在最大采收率目标下,明确不同聚驱阶段合理压力梯度界限范围,以及达到合理压力梯度界限范围所要求的注采参数,进而优化指导注入井参数调整及适当放大采出井工作参数,提高地层存聚率,扩大聚合物在油层中的波及体积。研究成果为区块下一步调整指明方向,改善了聚驱效果,同时也为其它聚驱区块开发调整提供参考依据。
[Abstract]:The scale of the river channel sand body in the first class oil reservoir of the Pu-1 formation in the eastern part of Nanqi-Xingyi area has become smaller, the reservoir conditions have become worse, the water cut in the water drive stage is comprehensive, the degree of recovery and the ratio of water flooding thickness are high. There are three problems since polymer injection: first, slow effect, uneven effect and low effective ratio; second, high viscosity loss, high return pressure, high submergence ratio; third, low pressure gradient and high flow pressure level in some well areas, without the use of expanded sweep volume. It affects the development effect of block polymer flooding. Because the injection-production pressure gradient is closely related to the development effect of polymer flooding, how to construct a reasonable pressure gradient of polymer flooding is particularly important. In order to understand the influence factors and variation characteristics of formation pressure during polymer flooding development, a fine three-dimensional geological model is established, and historical fitting is carried out by using numerical simulation software to study the thick viscosity and injection strength of formation pressure and polymer solution. The relationship between injection velocity, injection-production ratio, well fluid pressure, submergence degree, fluid recovery intensity and so on is discussed, and the characteristics of formation pressure variation in different stages are summarized. Finally, the prediction model of formation pressure is established. At the same time, the mathematical models of oil well inflow performance in different displacement stages are studied, and the reasonable flow pressure limits in different stages are established. The inflow performance of polymer flooding oil wells is the basis for analyzing the production state of oil wells and the key to reasonable design of lift mode and production system. In the process of polymer flooding, the oil well production fluid containing polymer has obvious non-Newtonian characteristics. Due to the effects of shearing and degradation, the rheology of formation fluid changes greatly. Therefore, the conventional inflow performance model can not be used to determine the inflow performance of this kind of wells. There is little research on reasonable flow pressure in polymer flooding production wells at home and abroad. Polymer flooding production fluid presents pseudoplasticity, fluid properties are greatly affected by concentration of polymer and water cut, combined with rheological characteristics of fluids in different stages of polymer flooding. On the premise of maximization of oil well production, the influence of high and low flow pressure on oil recovery is studied, and the optimum reasonable flow pressure limit at different stages is determined. In the early stage of polymer injection, 4.5m ~ 6 MPa, 3.4 ~ 4.5MPa, 4.5MPa, 45.5MPa, respectively. By studying the relationship between injection-production parameters and injection-production pressure difference of classified well groups, under the maximum recovery target, the reasonable limit range of pressure gradient in different stages of polymer flooding and the injection-production parameters required to reach the limit range of reasonable pressure gradient are determined. Then the parameters of injection wells are adjusted and the working parameters of production wells are appropriately enlarged to improve the formation accumulation rate and to expand the sweep volume of polymer in the reservoir. The research results show the direction of block next adjustment, improve the effect of polymer flooding, and also provide a reference for the development and adjustment of other polymer flooding blocks.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE357.46
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本文编号：1798089