齐家—古龙地区高台子致密油层物性下限确定方法

DETERMINING METHOD FOR THE LOWER LIMITS OF PHYSICAL PROPERTIES FOR GAOTAIZI TIGHT OIL RESERVOIRS IN QUIA-GULONG AREA

致密油层物性下限的确定对于发现致密油藏、提交储量具有重要意义。齐家—古龙地区高台子扶余油层储层致密,取心资料少,采用大型体积压裂后没有单层试油资料,因此无法应用常规油藏中的试油、经验统计和含油产状等方法确定储层物性下限。应用地层条件下的岩电实验数据并对比不同物性条件下驱替程度确定的渗透率下限为0.05×10^(-3)μm^2;应用核磁数据并对比饱和谱、离心谱确定的渗透率下限为0.04×10^(-3)μm^2;应用研究区黏度资料并根据黏度、流度及渗透率的关系确定的渗透率下限为0.05×10^(-3)μm^2。综合3种方法确定的渗透率下限为0.05×10^(-3)μm^2,对应的有效孔隙度为7%。实际井资料的试油结果表明,该区致密油层物性下限的确定结果可靠。

It is very important to determine the lower limits of the physical properties for the discovery of the tight oil reservoirs and reserves submission. Fuyu oil layers in Gaotaizi Formation in Qijia-Gulong area is characterized by tight property and few cored data, after adopting large-size volumetric fracturing, due to the lack of individual tested data, the limits can not be determined by the following conventional methods： oil testing, empirical statis- tics, oil occurrences and so forth. By means of the rock-electric experimental data under the stratigraphic condi- tions, and moreover the contrasts of the displaced degree in different physical property conditions, the permeabili- ty lower limit is determined to be 0. 05 ×10-3μm2 ; with the help of the nuclear magnetic resonance { NMR） data and comparisons of the saturation and centrifugal spectra, the permeability lower limit is restricted to be 0.04×10-3μm2 ; according to the viscosity data in the study area and moreover the relationships between the viscosity, mobility and permeability, the permeability lower limit is confirmed to be O. 05 ×10-3μm2. The permeability limit made by the comprehensive methods stated above is 0.05×10-3μm2, the corresponding effective porosity is 7%. The oil test results of the practical well data, the determined physical property limits of the tight oil reservoirs in the area are pretty reliable.