| The Qaidam Basin is currently the oil,natural gas,and coal exploration and development base in Qinghai Province.During the above-mentioned exploration of conventional energy minerals,non-conventional energy minerals such as oil sands,oil shale,coal-bed methane and sandstone uranium have been found to reach industrial grade.In particular,the northern edge of the Qaidam Basin is widely distributed in the second section of the Middle Jurassic Shimen Gou Formation,which is worth further exploration and development.According to the 5 million tons/year oil shale development project implementation plan of Qinghai chengda energy Co.,Ltd.,there is an urgent need to systematically carry out the evaluation of chaibei margin oil shale,preliminary understanding of the characteristics of oil shale in the region,guiding the establishment of oil shale exploration rights and the development of the next exploration work.Based on the principle of narrowing the scope of exploration and reducing the cost of discovery,this paper takes the object of study,and on the basis of the systematic collection of various kind-s of results,it is mentioned that the shale gas research project is initially identified as oil shale.Then we carry out special surface investigation,drilling Geological catalogs,Geophysical logging and sample analysis,etc..Finally,through the study of the characteristics of oil shale and the influence factors of its distribution,we obtain the rule of oil shale deposits,and provide reference for the future research area oil shale exploration and evaluation work.This paper systematically collects and collates data on the results of Geophysical exploration,d rilling and testing of coal field systems and petroleum systems,with the principle of narrowing the scope of exploration and reducing the cost of discovery.After carrying out the preliminary identifica tion of oil shale in the section 2 shale gas research work,we will continue to carry out special surIV face surveys of oil shale,drilling Geological catalogs,Geophysical logging,and sample analysis andanalysis.We will understand the characteristics of oil shale deposits,the characteristics of mineral body distribution,and study the influence factors affecting oil shale distribution.Summarize the law of oil shale deposits and provide reference for the future exploration and evaluation of oil shale in the research area.Through the systematic research work,it was found that the rock shale in the second section o f the area was individually mineralized and developed.It was generally co-associated with thick-laye r mud shale,and the local area was co-associated with the associated calcite vein.The gray-black o il shale contained pyrite nodules or particles.Logging has the characteristics of high acoustic time difference,high resistivity,low natural gamma,and low stratigraphic density.The thickness of oil sh ale varies from 1M to 12 m in each mining area,and the surface is exposed,and the maximum bur ied depth is greater than 1500 m.It consists of a number of independent rich centers and is charact erized by a thin spread of the middle thickness.The spread range is determined by the structural b oundary,the denudation boundary,and the sedimentary boundary.According to the results of oil shale industry analysis,the oil shale oil content in the research area is at a minimum of 3.5 %,a maximum of 11.5 %,and an average of 5.9 %,which is a low and Middle grade;The minimum ash is 49.85 <UNK> and the maximum is 88.35 <UNK>,most of which are within the range of 75 %-88 % and are high ash points;The lowest calorific value is 0.84 MJ/kg,the highest is 13.58 MJ/kg,the average is 7.94 MJ/kg,and the grade is intermediate;The minimum total sulfur content is 0.37 %,the maximum is 1.17 %,and the average is 0.53 <UNK>,which is an extremely low sulfur shale.Combined with oil shale organic matter elements and mirror characteristics,organic matter type s are dominated by Type II1,mainly derived from low aquatic organisms and algae,there is a smal l amount of land-based higher plant supply.The ribonite reflectivity(Ro)is between 0.3 and 0.6,an d it is in the immature-low maturity stage.In the clay minerals,the saponin accounts for between 50 and 70,and some samples have the phenomenon of the disappearance of saponin.The diagenesi s stage is in the early diagenesis stage B and the middle diagenesis stage A,which is presumed to be related to the uplift of the Late Jurassic tectonic extrusion and the short evolution of diagenetic compaction heat.The oil shale is formed in a warm-semi-arid semi-deep lake-deep lake phase reduction environment under stable subsidence and is affected by underwater gravity flow.The source of climate,sed imentary environment and organic matter directly affects the control of oil shale,the thickness distri bution and the oil content characteristics.Through the study of characteristics and occurrence regularity of oil shales,have certain guidin gsignificance for the establishment of oil shale exploration rights and future exploration work. |
PDF Full Text Request