Tight volcanic reservoirs, characterized by strong heterogeneity and a well-developed fracture network, are usually difficult to develop. The development of effective ways to enhance production in such reservoirs is an important task in research work for oil and gas field development. The method of enhancing production by imbibition is a promising technology for oil recovery in tight reservoirs. In this paper, based on the production data of horizontal wells in tight volcanic reservoirs, we have studied the imbibition mechanism during fracturing fluid flowback. Nuclear magnetic resonance (NMR) technology was used for analysis. First, the wire-cutting technique was used to simulate fractures generated by hydraulic fracturing in the core. Then the core was filled with quartz sand. Then the migration of fluid between small pores and macropores during the imbibition process was studied by low-field NMR analysis. The research results show that the imbibition displacement of fracturing fluid under high pressure can effectively increase the recovery rate, while the soaking time can affect the imbibition exchange of fluid between crack and matrix. Due to the small pore radius and high capillary resistance of the volcanic rock, the imbibition stability time is longer. The pore size distribution of volcanic rock was analyzed quantitatively by NMR and mercury intrusion porosimetry. The results show that the dynamic imbibition process occurs mainly in pores less than 2 ìm.

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使用核磁共振研究吸入生产机制的新方法

致密火山岩储集层非均质性强，裂缝网络发育，通常难以开发。开发此类储层增产的有效途径是油气田开发研究工作的一项重要任务。渗吸增产方法是一种有前景的致密油藏采油技术。本文以致密火山岩油藏水平井的生产资料为基础，研究了压裂液返排过程中的渗吸机理。核磁共振（NMR）技术用于分析。首先，使用线切割技术模拟岩心水力压裂产生的裂缝。然后用石英砂填充岩心。然后通过低场核磁共振分析研究了渗吸过程中流体在小孔和大孔之间的运移。研究结果表明，压裂液高压渗吸驱替可以有效提高采收率，而浸泡时间会影响裂缝与基质之间的渗吸交换。由于火山岩孔隙半径小、毛细管阻力大，吸水稳定时间较长。通过核磁共振和压汞孔隙率测定法定量分析了火山岩的孔径分布。结果表明，动态吸吸过程主要发生在小于2μm的孔隙中。研究结果表明，压裂液高压渗吸驱替可以有效提高采收率，而浸泡时间会影响裂缝与基质之间的渗吸交换。由于火山岩孔隙半径小，毛细管阻力大，吸水稳定时间较长。通过核磁共振和压汞孔隙率测定法定量分析了火山岩的孔径分布。结果表明，动态吸吸过程主要发生在小于2μm的孔隙中。研究结果表明，压裂液高压渗吸驱替可以有效提高采收率，而浸泡时间会影响裂缝与基质之间的渗吸交换。由于火山岩孔隙半径小，毛细管阻力大，吸水稳定时间较长。通过核磁共振和压汞孔隙率测定法定量分析了火山岩的孔径分布。结果表明，动态吸吸过程主要发生在小于2μm的孔隙中。通过核磁共振和压汞孔隙率测定法定量分析了火山岩的孔径分布。结果表明，动态吸吸过程主要发生在小于2μm的孔隙中。通过核磁共振和压汞孔隙率测定法定量分析了火山岩的孔径分布。结果表明，动态吸吸过程主要发生在小于2μm的孔隙中。