Studies For Water Flooding Characteristic Of Low-Permeability Sandstone Reservoirs In Shengli Oilfield

Currently around low permeability sandstone reservoir development problems,many scholars have done a lot of work research to adjust and improve the effectiveness of development.Some progress have made,especially in the technical aspects of the process of forming a number of specialized technical series.But some conflicts have not been resolved in oilfield water injection including difficult water-injection,water break-through early,water rises rapidly,and low efficiency of water injection and so on.The article conducted a lot of experimental studies based on Shengli Oilfield low permeability sandstone reservoir to investigate the influence mechanism between reservoir pore structure characteristics parameters,initial water saturation and water cut increasing regularity.Then made the research about the microscopic pore structure and driving pressure gradient for oil displacement efficiency of water law research.Solutions presented in this thesis can be summarized as follows:The internal mechanism about the change of two-phase flow capability is the change of microscopic pore structure.It can be descripted by the characteristic parameters of Structure coefficient.The law about water rise in low oil saturation sandstone reservoirs can be divided into three stages: the rapid ascent,stability and slow ascent fluctuations segment;its initial moisture content is determined by the original reservoir oil saturation,and can be quantified by laboratory experiments and forecasting.The characteristic structure coefficient is the main controlling factor to affect water drive efficiency in low permeability sandstone reservoirs.Different displacement pressure gradient under water oil displacement efficiency and relative permeability experiments and comparative experiments can draw the larger displacement pressure gradient.