Study On Oil Shale Resource Evaluation Method

Oil shale is an important supplementary energy resource for oil and gas. At present, the research of oil shale emphasized particularly on the genesis, the classification, the character and the manufacturability of oil shale, but the study on oil shale resource evaluation is still comparatively rare. The First National Oil Shale Resource Evaluation preliminarily established a set of oil shale resource evaluation method and correlative parameter criterion, but it mainly continued to use the evaluation thinking of solid mineral resources, the established oil shale resource evaluation methods and parameter system were still not complete and had some weaknesses.Based on a great lot of investigation on oil shale at home and abroad and solid works on the metallogenic geological research of oil shale, the thesis focused on the analysis of the metallogenic geological characters of oil shale in continental depression basin, then optimized and improved the current oil shale resources evaluation methods and parameter system aiming mainly at the evaluation of shale oil resource potential, and formed an comparative evaluation method system. Among them, volumetric method was to give emphasis to the bases of the detailed research on the metallogenic geology and the accurate analyzed and tested results, and made the evaluation results objective; But geologic analogue method emphasized on the analogue of metallogenic geological conditions centering on the metallogenic geological evaluation, which gave the resource potential of the evaluated unit as same as answered the question of resource distributions in space; The choose of oil shale resources evaluation methods depended primarily on the degree of oil shale exploration of evaluated areas, usually, we used the volumetric method in the high degree of exploration areas, used the volumetric method or geologic analogue method in middle degree of exploration areas, and used the geologic analogue method in low degree of exploration areas.The dissection of calibrated units is an important approach for summarizing the metallogenic geological characters of oil shale, verifying the applicability of oil shale resources evaluation methods and establishing the evaluation parameter system and choose value criterion. Oil shale in Nongan area of southern Songliao basin had the typical development characters of continental depression basin, and the area characterized by the high degree of oil shale exploration, the clear recognition on metallogenic geological regularity and the high ratio of discovered oil shale in the whole basin. By the dissection study of Nongan Oil Shale Mine Area, the thesis did an intensive research on the oil yield, thickness, area, resource abundance and technology mining coefficient of oil shale, established the quantitative model and choose value criterion for evaluating the oil yield of oil shale utilizing the log information and pyrolysis parameters, and established the choose value criterion of the oil shale technique mining coefficient under different conditions and different resource types; Based on the analysis of the metallogenic geological characters of oil shale in Nongan area of southern Songliao basin, according to the chief controlling elements of oil shale mineralization, the thesis established the evaluation parameters and choose value criterion of geologic analogue method, mainly including the palaeostructure conditions, depositional environment, palaeoclimatologic conditions and the organic geochemistry characters of oil shale. Among them, the palaeostructure conditions considered the distance of oil shale from the center of subsidence, the stability of oil shale formation and the complex degree of structure; the depositional environment considered the developed sedimentary facies of oil shale, the characters of sequence stratigraphy and the oxidizing reduction condition; the organic geochemistry characters of oil shale mainly considered the content of organic carbon, the types of organic material and the oil yield of oil shale .Nongan Oil Shale Mine Area is located in the southeast uplift of southern Songliao basin and lies in Nongan County of northern Changchun city, Jilin Province, which area is about 15752km2. According to the largest distribution range of oil shale formation, the section line of structure and the Second Songhua River, the thesis ascertained the boundary of the Mine Area. Oil shale deposited in the 1st member of Qingshankou formation and the 1st -2nd member of Nenjiang formation. During the oil shale depositional period, the basin was in the stage of depression, marked by heterogeneous whole subsidence and formed the unified depositional setting. Oil shale deposited in the anaerobic depositional environment with the semi-deep-deep lake facies, mainly developed in the highstand systems tract(HST) and transgressive systems tract(TST). The heavy-bedded black oil shale deposited in the 1st member of Qingshankou formation and the 2nd member of Nenjiang formation corresponded with the twice largest transgression in the deleveling curve of Songliao basin, which showed that oil shale was the product of the twice largest transgression period of Songliao basin. Oil shale was developed in humid-warm and tropic-subtropical climatic. The main types of organic material of oil shale wereâ… -â…¡1 types, and the second wasâ…¡2 type. The content of organic carbon was moderate, and was linearly and positively related to the oil yield of oil shale. Oil shale was in immature lithogenic stage.In the input and preserve condition of organic material of oil shale, the moderate content of organic carbon and the good types of organic material of oil shale in Nongan area displayed a good basic condition for oil shale mineralization, and during the oil shale depositional period, the water of lake basin was relatively steady, which provided a good preserve condition for organic material. Depositional environment, palaeoclimate and palaeostructure condition were the chief controlling elements of oil shale mineralization in Nongan area of southern Songliao basin. Oil shale mainly developed in the semi-deep -deep lake environment, the range of lake basin controlled the planar distribution of oil shale, and the times of transgression controlled the numbers of oil shale layers and influenced the vertical distribution of oil shale; The bloomed land plants under the humid-warm climate provided a great deal of terrestrial nutritive material for the lake and provided abundance material bases for forming oil shale. The climate condition controlled the types and preserve condition of organic material together with the anaerobic depositional environment; the palaeoclimate condition controlled the whole depositional character of the basin, mainly manifested in the control of the depositional center of oil shale and the accumulation center of rich oil shale. The center of subsidence in the basin basically agreed with the depositional center, and the oil yield and thickness of oil shale were gradually larger to the center of subsidence.The thesis evaluated the oil shale resources of Nongan area with the volumetric method and geologic analogue method, the results showed that the proved shale oil resources were 1.4 billion ton, the potential shale oil resources were 5.3 billion ton, and Nongan area was the richest region of oil shale in China. In addition, there were plentiful metal, rare metal and rare earth elements in oil shale, so oil shale not only could extract the shale oil, but also could be used to generate electricity, petrochemical complex, and the left ashes after extracting the shale oil could be used to make the building materials (the haydite and cement) and the chemical fertilizer for village. Hence, the best way for multi-purpose utilization of oil shale is to integrate the oil-refining, chemicals production, generation of electricity, metal refining and building materials production to reduce the cost. At this point, the exploitation and utilization of oil shale in Nongan area would have great multi-purpose development prospect.