摘要
和田河气田是塔里木盆地已发现的大型碳酸盐岩气田 ,其奥陶系储集层属于裂缝 孔洞型碳酸盐岩。应用分形理论研究该气田 4口井奥陶系 70m长岩心中的裂缝 ,将裂缝条数和统计用的岩心长度各取自然对数 ,二者之间呈现明显的正相关关系 ,4口井的线性相关系数都大于 0 .97。根据裂缝分维数的地质意义 ,位于构造轴部的井比位于边部井的分维数要大 ,表明构造轴部比边部裂缝发育 ;位于构造轴部的井分维数值由东向西依次减小 ,反映构造东部比西部裂缝发育 ;自上往下分维数值也依次减小 ,说明裂缝发育程度由上向下降低。这种分维数计算结果符合断背斜的裂缝系统分布特征。裂缝分维数与储集层物性具有较好的正相关关系 (与孔隙度的相关系数达 0 .90 49,与渗透率的相关系数高达 0 .9968)。通过计算裂缝分维数 ,可以定量预测裂缝 孔洞型储集层的裂缝发育带和有利储集层分布区 ,指导油气勘探。图 3表 3参
Hetianhe gas field is a large Carbonate rock gas field discovered in Tarim basin. Its Ordovician reservoir is of fractured cavernous carbonate. The authors analyzed fractures of Ordovician cores of 70m long from 4 wells of the gas field with fractal theory, and took the logarithm of number of fractures and length of the cores respectively, as a result, positive mutuality is obviously presented between the two sets of logarithmic values. Linear correlation coefficients of 4 wells are all more than 0.97. According to geologic meanings for fractal dimension of the fractures, the value of fractal dimension of the fractures from the wells located at the axis of the structure is larger than that from the wells located at side of the structure, indicating the fractures at axis of structure are more developable than that at side of the structure; the value of fractal dimension of the fractures from the wells located at the axis of the structure decreases from east to west, showing the fractures in the east of structure are more developable than that in the west of the structure; the value of fractal dimension of the fractures decreases from above to below, revealing the developable level of the fractures declines from above to below. The calculating results of the fractal dimension tallies with distribution features of the fractures in fault sealed anticline. The fractal dimension of the fractures has a good positive mutuality on physical properties of the reservoir (correlation coefficient is 0.9049 to porosity and 0.9968 to permeability). The fractures,developing zones of fractured cavernous reservoirs can be quantitatively predicted by calculating fractal dimension of the fractures and favorable distributing area of the reservoirs, and it can give a guide to the oil and gas exploration.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2001年第3期46-48,共3页
Petroleum Exploration and Development
关键词
和田河气田
碳酸盐岩
岩心裂缝
分维数
物性
油气勘探
Hetian, Large field, Carbonate rock, Structure, Fracture (rock), Fractal, Analysis, Reservoir, Porosity, Permeability
