鄂尔多斯盆地红河油田裂缝识别

Fracture Identification in Honghe Oilfield,Ordos Basin

红河油田为典型的低孔隙度低渗透率油藏,储层裂缝广泛发育。通过岩心观察、成像测井识别等手段对其裂缝特征进行了描述。研究发现该研究区裂缝在岩心上多为高角度裂缝和垂直裂缝,在成像上多为正弦波曲线显示。裂缝在双感应、八侧向和阵列感应测井曲线上均显示低值,八侧向与双感应测井值正差异;双井径微扩径,声波、中子值增大,密度值减小;在双感应电阻率正异常显示高值,八侧向电阻率值在层的上部与双感应电阻率值正差异,在层的下部与双感应电阻率值负差异;声波、密度值减小,中子值增大。裂缝在变尺度分形曲线的R/S曲线上偏离了原来的趋势线,成为近似一直线段。探讨了裂缝发育程度与单井产能的关系。研究结果表明裂缝发育段其产能普遍增高。经岩心和成像资料验证,裂缝识别率较高。

Honghe oilfield is a typical low porosity and low permeability reservoir and the reservoir fractures are developed widely . According to the observation of core and imaging logging data ,there are mostly high‐angle and vertical fractures in the reservoir .They are mostly sinusoid display in imaging . There are two types of response characteristics of fractures in conventional logging curves :① dual induction ,8 laterolog and array induction data are all low ,8 laterolog resistivity log data and dual induction resistivity log data appear to be positive difference ,dual diameters extension is minor ,sonic log data and neutron log data are high ,and density log data are low . ② High dual induction resistivity log data appear to be positive difference ,8 laterolog log data and dual induction data are positive difference in the upper layers and are negative difference in the lower layers .Sonic and density log data are low ,neutron log data are high . Fractures are deviation from the trend line in the R/S curve of variable scale analysis map ,and became approximate line segment .It has been verified by core and imaging data that the method has achieved a high fracture identification rate . Also , the fractures development is predicated and its relationship with single well productivity is discussed . The results show that the single well productivity is improved in the fractures developed formations . Drilling core and image log data show this method has high fracture identification rate .