徐家围子断陷致密砂砾岩束缚水饱和度测定研究

发布时间：2018-01-09 02:29

本文关键词：徐家围子断陷致密砂砾岩束缚水饱和度测定研究　出处：《东北石油大学》2017年硕士论文　论文类型：学位论文

【摘要】：徐家围子断陷位于松辽盆地中部徐家围子-北安断陷带上,西邻中央古隆起,东接朝阳沟凸起,北部以鞍部与林甸黑鱼泡断陷沟通,南与王府断陷相连。随着常规油气资源的逐步消耗,勘探开发难度的增加,非常规油气的重要性日益凸显,其中致密油气是目前非常规油气资源中最为现实的勘探目标。徐家围子断陷多口井已在沙河子组钻遇致密砂砾岩气,在其地层评价中,束缚水饱和度是体积法计算储量时的重要参数之一,也是区分水层和油气层,计算油水相对渗透率和产水率的关键参数,因此徐家围子断陷致密砂砾岩束缚水饱和度测定变得至关重要。本文以徐家围子断陷沙河子组致密砂砾岩为研究对象,以核磁共振理论、毛管理论和渗流力学理论等基本理论为指导,综合运用各种实验手段,对沙河子组致密砂砾岩束缚水饱和度进行测定,并研究常温常压与地层温度压力下束缚水饱和度的变化情况,最后应用束缚水饱和度确定致密储层的下限。实验结果表明:常温常压条件下,气-水相渗测量的束缚水饱和度普遍较高,最高可达90%,平均为79.8%,并且渗透率越低,束缚水饱和度就越大;常温常压条件下,核磁共振方法测量的束缚水饱和度与气-水相渗方法基本吻合,其次是恒速压汞方法,高压压汞方法吻合的最差;核磁共振测量的常温常压束缚水饱和度明显高于地层高温高压条件下气驱测量的束缚水饱和度,二者差值大约为32%,在实际应用时应对常温常压核磁束缚水饱和度进行校正,校正量大致为30%,校正后的核磁束缚水饱和度平均值大约为55%;岩石可动流体所占孔隙体积低于束缚水体积,半径较大的储集空间中也可能存在束缚水;粗砂岩粒度较粗,分选较好,岩石抗压性较强,喉道半径要高于砾岩和细砂岩,具有较低的束缚水饱和度;孔隙型岩石的泥质含量少,喉道半径较大、孔隙较发育,孔隙和喉道间连通性最好,具有较低的束缚水饱和度;利用束缚水饱和度确定致密储层下限对应的喉道半径约为27nm。通过对沙河子组致密砂砾岩束缚水饱和度的研究分析,为进一步评价徐家围子油气层潜力,确定油气富集区,优选布井有利区等工作打下牢固基础,也为实现研究区的油气勘探突破,提高资源采收率,提供了重要的理论依据。
[Abstract]:Xujiaweizi fault depression is located in the Xujiaweizi-Beian fault depression belt in the middle of Songliao basin, adjacent to the central ancient uplift in the west, and connected to the Chaoyang gully uplift in the east, and to the north to communicate with the Lingdian black fish bubble fault depression in the north. With the gradual consumption of conventional oil and gas resources and the increasing difficulty of exploration and development, the importance of unconventional oil and gas becomes increasingly prominent. Dense oil and gas is the most realistic exploration target in unconventional oil and gas resources at present. Several wells in Xujiaweizi fault depression have been drilled in Shahezi formation with tight grit gas, and in their stratigraphic evaluation. The irreducible water saturation is one of the important parameters in the calculation of reserves by volume method. It is also the key parameter to distinguish the water reservoir from the oil and gas reservoir and to calculate the relative permeability and water production rate of oil and water. Therefore, the measurement of irreducible water saturation of dense sand gravel in Xujiaweizi fault depression becomes very important. In this paper, the tight sand gravel of Shahezi formation in Xujiaweizi fault depression is taken as the research object, and the nuclear magnetic resonance theory is used. Under the guidance of capillary theory and percolation mechanics theory, the irreducible water saturation of tight gravel rock in Shahezi formation was measured by various experimental methods. The change of irreducible water saturation under atmospheric pressure and formation temperature and pressure is studied. Finally, the lower limit of tight reservoir is determined by irreducible water saturation. The experimental results show that: under normal temperature and atmospheric pressure. The irreducible water saturation measured by gas-water permeation is generally high, the highest is 90, the average is 79.8, and the lower the permeability, the greater the irreducible water saturation. Under normal temperature and atmospheric pressure, the irreducible water saturation measured by nuclear magnetic resonance method is basically consistent with gas-water phase infiltration method, followed by the constant velocity mercury injection method, and the high pressure mercury injection method is the worst. The irreducible water saturation at room temperature and atmospheric pressure measured by nuclear magnetic resonance is obviously higher than that measured by gas drive at high temperature and high pressure, and the difference between them is about 32%. In practical application, the irreducible water saturation of nuclear magnetic field at room temperature and atmospheric pressure should be corrected, the correction amount is about 30 and the average value of the corrected irreducible water saturation is about 55. The pore volume of rock movable fluid is lower than that of irreducible water, and there may be bound water in reservoir space with larger radius. The coarse sandstone has higher grain size, better sorting, stronger rock compressive resistance, higher throat radius than conglomerate and fine sandstone, and lower irreducible water saturation. The pore type rocks have less muddy content, larger throat radius, more developed pores, the best connectivity between pore and throat, and low irreducible water saturation. The throat radius corresponding to the lower limit of tight reservoir determined by irreducible water saturation is about 27 nm. Through the study and analysis of the irreducible water saturation of dense gravel rock in Shahezi formation, the potential of Xujiaweizi oil and gas reservoir can be further evaluated. The determination of oil-gas rich areas and favorable areas for selecting well distribution have laid a solid foundation and provided an important theoretical basis for the breakthrough of oil and gas exploration and the improvement of oil and gas recovery in the study area.
【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】：P618.13

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