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为研究裂缝力学层控发育模式,进而实现对裂缝型油气藏碳酸盐岩层系裂缝发育特征有效预测,通过对新疆西克尔露头区地层产状平缓奥陶系碳酸盐岩层系3个野外露头剖面(21号剖面(39°50′17.34″N,77°28′36.12″E)、32号剖面(39°50′18.18″N,77°28′25.62″E)以及43号剖面(39°50′10.88″N,77°28′26.1″E))垂向裂缝生长特征的统计分析,结合沉积旋回的划分结果,揭示了不同剖面力学界面的分布特征以及力学单元控制下各剖面的裂缝密度.结果表明,21号剖面的平均裂缝密度为7.1条/m,远大于32号剖面的2.2条/m以及43号剖面的2.9条/m.分别从岩性特征、力学单元厚度以及应力状态等方面探讨其对于3条剖面裂缝密度差异分布的影响与控制.碳酸盐岩层系裂缝的密度随灰岩中泥晶含量的增加而递增,颗粒灰岩中裂缝的密度明显低于泥晶灰岩;受压力影作用的影响,力学单元的厚度与裂缝的密度呈负相关,力学单元越厚则裂缝密度越低.43号剖面与32号剖面的裂缝饱和度均大于0.8,接近裂缝饱和状态;而裂缝平均密度最大的21号剖面其裂缝饱和度仅为0.6,为不饱和状态,裂缝的平均密度与其饱和度值呈负相关.
In order to study the stratigraphic development model of the fracture mechanics and to predict the fracture development characteristics of carbonate reservoirs in the fractured reservoirs effectively, three Ordovician carbonate strata in the outcropping area of the western Kerr outcrop are developed. Outcrop profile (section 21 (39 ° 50’17.34 “N, 77 ° 28’36.12” E), section 32 (39 ° 50’18.18 “N, 77 ° 28’25.62” E) and section 43 ° 50’10.88 “N, 77 ° 28’26.1” E)). Based on the results of the division of sedimentary cycles, the distribution characteristics of mechanical interfaces at different sections and the fractures of sections under the control of mechanical units The results show that the average fracture density of No.21 section is 7.1 / m, which is much larger than 2.2 / m of section 32 and 2.9 / m of section 43, respectively.The lithologic characteristics, mechanical unit thickness and stress state Etc. The density of fractures in carbonate strata increases with the increase of the amount of the clay in the limestone.The density of the fractures in the granular limestone is obviously lower than that of the smectite Rock; influence of pressure shadow effect, thickness and crack of mechanical unit Density is negatively correlated, and the thicker the mechanical unit, the lower the crack density.The crack saturation of section No.43 and section 32 are all greater than 0.8, which is close to the saturated state of crack.The crack saturation of section 21 with the highest average crack density is only 0.6. In the unsaturated state, the average density of fractures is negatively correlated with the saturation value.