密闭取心饱和度校正方法研究

Study on Saturation Correction of Sealing Core Constrained by Fluid Viscosity and Relative Permeability

胜利油田目前已进入特高含水期,求准油层油水饱和度是寻找剩余油和提高开发效果的关键和难点。但是目前较准确的密闭取心所测得的油水饱和度与实际地层条件下的饱和度也存在较大的误差。通过密闭取心影响油水饱和度的因素分析和定量计算各种影响饱和度的地质和开发因素,把排出液量按渗流力学原理进行分配,克服了微间隙的影响。通过测量流体黏度和相渗参数建立数学模型,得到了地层条件下的饱和度数据,使地层的驱油效率计算趋于合理。其理论模型具备通用性,具有很强的应用性和可推广性,在现场试验和实际计算中取得了很好的效果。

The Shengli oilfield has entered the high water stage, and the correct oil and water saturation is the key and difficulty for the location of remaining oil and enhancing of development performance. Whereas, the theo- retically most correct approach to measure the saturation, the sealing core, is always not in correspondence with the actual saturation under the formation conditions. Through qualitatively analyzing factors causing saturation measure- ment errors in sealing core and quantitatively calculating the geological and development factors that may affect the measurement of saturation, the influence of micro-space is eliminated by means of reallocation of expelled fluid ac- cording to the fluid mechanics theory, and then the mathematical model to calculate the saturation under formation condition is proposed through the measurement of fluid viscosity and relative permeability. This mathematical model is compatible with the present reservoir types and may be applied in field scale, and has been proved feasible by the pilot in the field.