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陕甘宁盆地奥陶系碳酸盐古风化壳天然气储集层中存在丰富的高岭石族矿物，经扫描电镜观察、单矿物样的Ｘ射线衍射、红外吸收光谱及差热分析，确认为地开石，而不是高岭石。由于地开石的存在反映酸性的成岩介质，这不利于作为孔隙封堵物的高铁、锰方解石和白云石的沉淀，而有利于碳酸盐矿物的溶解，对埋藏成岩过程中储层孔隙的保存与发育极为有利；同时由于地开石的分子体积小于高岭石，高岭石向地开石的转化会有多余的孔隙空间出现．并形成更多的晶间孔隙，因而地开石通常是好储层的指示矿物。此外．据该地开石形成温度判断，奥陶系碳酸盐储层所经历的最大古地温为１４０～１６０℃。
There are abundant kaolinite minerals in Ordovician carbonate ancient weathering crust natural gas reservoirs in the Shan-Gan-Ning basin. The results of scanning electron microscopy, single mineral sample X-ray diffraction, infrared absorption spectrum and differential thermal analysis confirm that Rock stone, not kaolinite. Because the presence of dickite reflects acidic diagenetic media, this is not conducive to the precipitation of high-speed iron, manganese calcite and dolomite as pore occlusions, but is favorable for the dissolution of carbonate minerals. Preservation and development is extremely beneficial; at the same time as the dickite molecular volume smaller than kaolinite, kaolinite to dickite conversion will have extra pore space. And more intergranular pores are formed, thus dickite is often the indicator mineral for good reservoirs. In addition. According to the formation of rock to determine the temperature of the Ordovician carbonate reservoirs experienced the largest ancient ground temperature of 140 ~ 160 ℃.