Organization
Shaanxi Key Laboratory of Well Stability and Fluid &
Rock Mechanics in Oil and Gas Reservoirs, Xi′an shiyou University, Xi′an 710065, China
College of Petroleum Engineering, Xi′an shiyou University, Xi′an 710065, China
No.11 Oil Production Plant, Changqing Oilfield Company, PetroChina, Qingyang 745000, China
Oil and Gas Technology Research Institute, Changqing Oilfield Company, PetroChina, Xi′an 710018, China
摘要
常规粒径匹配理论认为，聚合物微球能否进入地层孔隙并向深部运移，取决于粒径和地层孔喉直径的匹配关系，但无法充分解释纳米聚合物微球粒径越小、调驱效果越好的现象。文中根据微观实验明确了纳米聚合物微球在地层中的主要作用形式，建立了纳米聚合物微球沉积调控关键渗流参数数学模型，同时建立了2种基于毛细管模型的聚合物微球调驱数学模型，并通过算例对模型验证。研究结果表明：纳米聚合物微球在孔隙中的作用形式主要为沉积，通过沉积使得液流部分转向，进而达到扩大波及体积的目的；纳米聚合物微球调控储层渗透率的作用机理，是沉积后改变了孔隙的比表面积；算例表明，纳米聚合物微球通过沉积调驱的效果优于常规微球的封堵作用，也与数学模型及现场使用结果相符。该研究揭示了纳米聚合物微球深部调驱机理，为现场使用提供了理论依据。
Abstract
12Conventional particle size matching theory holds that whether polymer microspheres can enter formation pore and migrate deep depends on the matching relationship between particle size and formation pore throat diameter, but it cannot fully explain the field application phenomenon of smaller particle size, better profile control and flooding effect of nano-polymer microspheres. In this paper, the main action forms of nano-polymer microspheres in the formation are defined based on micro-experiments. Mathematical model of key seepage parameters for deposition control of nano-polymer microspheres was established. Two kinds of polymer microsphere profile control and flooding mathematical models based on capillary model were established and validated by numerical examples. The results show that the main form of action of nano-polymer microspheres in the pore is deposition, which makes the liquid flow partially change its direction to expand the sweep volume; the mechanism of nano-polymer microspheres regulating reservoir permeability is that the internal specific surface area of the pore is changed after deposition; the effect of nano-polymer microspheres through deposition is better than that of conventional micro-flooding by an example. The plugging effect of the ball is consistent with the mathematical model and field application results. This study reveals the deep profile control mechanism of nano-polymer microspheres and provides theoretical support for field use.
论文详情