深层富钾卤水的地球物理探测技术及应用——以江陵凹陷为例

上世纪在江陵凹陷的石油钻孔中发现了深层富钾卤水矿层,但是卤水矿层的空间展布一直不清。借用油气勘探领域中地球物理储层预测方法和理论,利用钻孔对矿层的垂向高分辨率的识别,标定到三维地震剖面上,利用多种地震属性横向高分辨率识别卤水矿层,预测矿层的空间分布,为靶区钻孔的部署提供依据。文章利用已经发现富钾卤水矿层的路9井的资料,开展模型正演,发现地震中振幅、频率、波形等属性可以较好地识别卤水矿层;将路9井的卤水矿层标定到地震剖面上,通过提取地震属性,识别出的富钾卤水矿层平面面积达5.53 km2;在该富钾卤水区中部署的岗钾1井,钻探获得高产富钾卤水矿层,验证了地球物理探测深层富钾卤水方法的正确性。

Application of geophysical detection method to exploration of deep potassium- rich brine formation: A case study of Jiangling Depression

Large quantities of deep potassium-rich brine seams were found in the petroleum drill holes in the Jianglin Depression in the last century; nevertheless, spatial distribution of the brine deposits remain unknown. On the basis of geophysical methods and theories used in reservoir prediction of hydrocarbon exploration, spatial distribution of the brine deposits can be predicted by identifying brine seams utilizing high lateral resolution of multiple seismic attributes which have been calibrated in 3-D seismic profile by diagnosing high vertical resolution of the brine deposits using drilling holes, so as to provide the basis for drilling brine wells in the target area. Using data from Well Lu-9 in which potassium-rich brine seams had been found, the authors performed forward modeling in this study. It is shown that the brine seams can be identified utilizing such seismic attributes as amplitude, frequency, and wave pattern, that through calibrating the brine seams of Well Lu-9 in a seismic profile, the identified brine seams exhibit an planar area of 5.53 km2 based on extraction of seismic attributes, and that the geophysical method could be correctly verified for investigation of deep potassium-rich brines by encountering productive potassium -rich brine seams in Well Gangjia-1 which was drilled in the middle part of an identified potassium-rich brine area.