In order to develop appropriate reservoir protection measures in the northern margin of the Qaidam Basin and improve its oil and gas recovery efficiency,characteristics of clay minerals from eleven clay rock samples f...In order to develop appropriate reservoir protection measures in the northern margin of the Qaidam Basin and improve its oil and gas recovery efficiency,characteristics of clay minerals from eleven clay rock samples from the northern margin of the Qaidam Basin were investigated using X-ray diffraction analysis,the Scanning Electron Microscope（SEM）and energy spectrum analysis.Clay mineral composition and distribution characteristics of the main hydrocarbon reservoirs,i.e.,from the Jurassic and Paleogene-Neogene,were explored.We analyzed the main factors which affected these attributes.The results show that the major clay minerals in the northern margin are chlorite,kaolinite,illite,smectite and illite/smectite inter-stratified minerals.Illite is the most widely spread clay mineral in this area. Chlorite is mainly found in the entire Neogene and in shallow horizons of the Paleogene.Smectite is enriched in the shallow Paleogene-Neogene.There are large amounts of kaolinite and illite/smectite inter-stratified minerals in the Jurassic.The major factors affecting the different development of clay minerals in the region are properties of parent rocks,paleoclimate and paleowater media conditions, diagenesis transformation,tectonic and terrain conditions.展开更多
Located in the northern Qinghai-Tibet plateau, Qaidam Basin is surrounded by the East Kunlun Mountains in the south, Qilian Mountains in the north, and Altun Mountains in the west. With an area of 121,000 square kilom...Located in the northern Qinghai-Tibet plateau, Qaidam Basin is surrounded by the East Kunlun Mountains in the south, Qilian Mountains in the north, and Altun Mountains in the west. With an area of 121,000 square kilometers （km^2）, Qaidam Basin is about 850 kilometers （km） long from east to west and 150-300km wide from south to north. Three sets of sedimentary formations had developed in the basin, including Palaeozoic, Mesozoic, and Cenozoic strata. The Mesozoic-Cenozoic sedimentary rock of the basin covers an area of 96630 km^2, with its maximum thickness achieving 17200m and volume being about 600,000km^3. 2019 various exploratory wells （2.7386 million meters of drilling footage in total） have been completed so far, 62291 kilometers of 2-D and 2754 km^2- of 3-D seismic exploration as well as geophysical and geochemical exploration such as gravity, electricity method, microgravity, magnetotelluric method （MT）, and continuous electromagnetic profiling （CEMP） have been carried out since the surface geologic survey, drilling, and seismic exploration were initiated in 1954, 1955, and 1956 respectively.展开更多
基金provided by the National Petroleum and Gas Resources Strategic Area Selection Survey & Evaluation projects in 2005,is gratefully acknowledged.
文摘In order to develop appropriate reservoir protection measures in the northern margin of the Qaidam Basin and improve its oil and gas recovery efficiency,characteristics of clay minerals from eleven clay rock samples from the northern margin of the Qaidam Basin were investigated using X-ray diffraction analysis,the Scanning Electron Microscope（SEM）and energy spectrum analysis.Clay mineral composition and distribution characteristics of the main hydrocarbon reservoirs,i.e.,from the Jurassic and Paleogene-Neogene,were explored.We analyzed the main factors which affected these attributes.The results show that the major clay minerals in the northern margin are chlorite,kaolinite,illite,smectite and illite/smectite inter-stratified minerals.Illite is the most widely spread clay mineral in this area. Chlorite is mainly found in the entire Neogene and in shallow horizons of the Paleogene.Smectite is enriched in the shallow Paleogene-Neogene.There are large amounts of kaolinite and illite/smectite inter-stratified minerals in the Jurassic.The major factors affecting the different development of clay minerals in the region are properties of parent rocks,paleoclimate and paleowater media conditions, diagenesis transformation,tectonic and terrain conditions.
文摘Located in the northern Qinghai-Tibet plateau, Qaidam Basin is surrounded by the East Kunlun Mountains in the south, Qilian Mountains in the north, and Altun Mountains in the west. With an area of 121,000 square kilometers （km^2）, Qaidam Basin is about 850 kilometers （km） long from east to west and 150-300km wide from south to north. Three sets of sedimentary formations had developed in the basin, including Palaeozoic, Mesozoic, and Cenozoic strata. The Mesozoic-Cenozoic sedimentary rock of the basin covers an area of 96630 km^2, with its maximum thickness achieving 17200m and volume being about 600,000km^3. 2019 various exploratory wells （2.7386 million meters of drilling footage in total） have been completed so far, 62291 kilometers of 2-D and 2754 km^2- of 3-D seismic exploration as well as geophysical and geochemical exploration such as gravity, electricity method, microgravity, magnetotelluric method （MT）, and continuous electromagnetic profiling （CEMP） have been carried out since the surface geologic survey, drilling, and seismic exploration were initiated in 1954, 1955, and 1956 respectively.
