scholarly journals Hydrocarbon generation potential evaluation of coal shale gas of Permo-Carboniferous in Jiyang Depression

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Pingping Li ◽  
Dawei Lv ◽  
Huiyong Wang ◽  
Changyong Lu
Keyword(s):  
Organic Matter ◽  
Shale Gas ◽  
Source Rocks ◽  
Maturity Stage ◽  
Hydrocarbon Generation ◽  
Gas Generation ◽  
Jiyang Depression ◽  
Hydrocarbon Generation Potential ◽  
Hydrocarbon Source Rocks ◽  
Generating Capacity

This paper studied the residual strata distribution of Carboniferous-Permian in Jiyang Depression, the organic geochemical characteristics of shale and the correlation of hydrocarbon-generating potential of shale by applying geochemistry, petroleum geology and coal geology, for study hydrocarbon generation potential of Permo-Carboniferous coal shale in Jiyang Depression. The results show that the thickness of Carboniferous-Permian residual strata in Jiyang Depression is generally 200-800 m, the thickest can reach 900 m; coal shale has good organic matter abundance and is type III kerogen, which is conducive to gas generation, and organic matter maturity reaches maturity-higher maturity stage; Benxi Formation and Taiyuan Formation have better hydrocarbon generation potential; medium to good hydrocarbon source rocks can be found in every sag of Shanxi Formation hydrocarbon source rocks, but the scope is limited, and the overall evaluation is still medium. Compared with other areas in China, it is found that the hydrocarbon-generating capacity of coal-bearing shale of Carboniferous-Permian in Jiyang Depression is generally at a medium level, which has a certain shale gas exploration potential.

Petroleum Geochemistry of the Loperot-1 Well in Lokichar Basin, Kenya

2016 ◽  
Author(s):  
David M. Katithi ◽  
David O. Opar
Keyword(s):  
Organic Matter ◽  
Source Rock ◽  
Shale Gas ◽  
Source Rocks ◽  
Geochemical Data ◽  
Mature Stage ◽  
Type I ◽  
Hydrocarbon Generation ◽  
Gas Generation ◽  
Gas Targets

ABSTRACT The work reports an in-depth review of bulk and molecular geochemical data to determine the organic richness, kerogen type and thermal maturity of the Lokhone and the stratigraphically deeper Loperot shales of the Lokichar basin encountered in the Loperot-1 well. Oil-source rock correlation was also done to determine the source rocks’ likelihood as the source of oil samples obtained from the well. A combination of literature and geochemical data analyses show that both shales have good to excellent potential in terms of organic and hydrogen richness to act as conventional petroleum source rocks. The Lokhone shales have TOC values of 1.2% to 17.0% (average 5.16%) and are predominantly type I/II organic matter with HI values in the range of 116.3 – 897.2 mg/g TOC. The Lokhone source rocks were deposited in a lacustrine depositional environment in episodically oxic-dysoxic bottom waters with periodic anoxic conditions and have Tmax values in addition to biomarker signatures typical of organic matter in the mid-mature to mature stage with respect to hydrocarbon generation and immature for gas generation with Ro values of 0.51 – 0.64%. The Loperot shales were shown to be possibly highly mature type II/III source rocks with TOC values of 0.98% – 3.18% (average 2.4%), HI of 87 – 115 mg/g TOC and Ro of 1.16 – 1.33%. The Lokhone shale correlate well with the Loperot-1 well oils and hence is proposed as the principal source rock for the oils in the Lokichar basin. Although both source rocks have good organic richness to act as shale gas plays, they are insufficiently mature to act as shale gas targets but this does not preclude their potential deeper in the basin where sufficient gas window maturities might have been attained. The Lokhone shales provide a prospective shale oil play if the reservoir suitability to hydraulic fracturing can be defined. A basin wide study of the source rocks thickness, potential, maturation and expulsion histories in the Lokichar basin is recommended to better understand the present-day distribution of petroleum in the basin.

Biomarker Geochemistry and Hydrocarbon Generation Potential of the Evaporites in Dongying Lacustrine Basin

2012 ◽  
Vol 616-618 ◽  
pp. 1042-1047
Author(s):  
Zhong Hong Chen
Keyword(s):  
Organic Matter ◽  
Hydrocarbon Generation ◽  
Lacustrine Basin ◽  
Hydrocarbon Generation Potential ◽  
Deep Wells ◽  
Generating Capacity ◽  
High Maturity ◽  
Different Response ◽  
Hydrocarbon Expulsion ◽  
Rock Eval

To investigate hydrocarbon potential of the evaporites, some deep wells such as Haoke-1 well and Fengshen-2 well were intensively cored, tested by TOC, Rock-Eval, and chromatography and mass spectrometry and evaluated using geochemistry of biomarker and hydrocarbon generation. High content of gammacerane and low Pr/Ph was exhibited in the evaporite system compared to the non-evaporite system. Different response of biomarkers parameters for the different sedimentary systems was exhibited, such as C19/(C19+C23) terpanes, C29/(C27+C28+C29) steranes, C24/C23 and C22/C21 tricyclic terpane. The evaporites and mud stones have the capacity to generate and expel hydrocarbons. The tested samples were mostly typeⅠand typeⅡ1 of organic matter, and their original generating capacity can reach 40 mg/g rock and 20 mg/g rock respectively. The efficiency of hydrocarbon expulsion reached 60%, but the distribution of organic matter and its generative potential was highly variable. In general, the mudstones show greater generative potential than the evaporites. High maturity severely reduced the capacity of their rocks to generate and expel petroleum.

scholarly journals Source Rock Evaluation and Hydrocarbon Generation Model of a Permian Alkaline Lakes—A Case Study of the Fengcheng Formation in the Mahu Sag, Junggar Basin

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 644
Author(s):  
Yong Tang ◽  
Wenjun He ◽  
Yubin Bai ◽  
Xiang Zhang ◽  
Jingzhou Zhao ◽  
...  
Keyword(s):  
Organic Matter ◽  
Evaluation Criteria ◽  
Junggar Basin ◽  
Source Rocks ◽  
Geochemical Data ◽  
Generation Model ◽  
Hydrocarbon Generation ◽  
High Hydrocarbon ◽  
Hydrocarbon Generation Potential ◽  
Alkaline Lake

The alkaline lake source rocks of the Fengcheng Formation are developed in the Mahu Sag of the Junggar Basin. Different from traditional continental fresh water and saltwater lake source rocks, alkaline lake source rocks lack targeted evaluation criteria, and it is unknown whether their hydrocarbon generation models are consistent with traditional models. Therefore, in the present study, evaluation standards and hydrocarbon generation models of alkaline lake source rocks are discussed based on geological and organic geochemical data and a systematic summary of the geochemical characteristics of the Fengcheng Formation source rocks. The Fengcheng Formation source rocks are mainly diamictite with mixed argillaceous rock and dolomite; most total organic carbon (TOC) values range from 0.2–1.4%; and the kerogen is primarily oil-prone type II, reaching low- to high-maturity stages. Based on the types of organic matter in source rocks and the relationships between organic matter abundance parameters, the evaluation standard of alkaline lake source rocks is proposed. The Fengcheng Formation is mainly composed of good to excellent source rocks (55.5%) with high hydrocarbon generation potential. The single-peak hydrocarbon generation model of the Fengcheng Formation is similar to that of traditional freshwater or saltwater lakes, with a high hydrocarbon generation rate, two to five times that of the traditional model; its main particularity is in the formation of naphthenic crude oil from the kerogen of bacteria and algae. A new understanding of the hydrocarbon generation potential and model of alkaline lake source rocks in the Fengcheng Formation can provide support for tight oil and shale oil exploration in the Mahu Sag.

scholarly journals Climate-Provenance Effect on the Organic Matter Enrichment of the Chang 9 Source Rocks in the Central Ordos Basin, China

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Ling Ma ◽  
Zhihuan Zhang ◽  
Weiqiu Meng
Keyword(s):  
Organic Matter ◽  
Chemical Weathering ◽  
Ordos Basin ◽  
Source Rocks ◽  
Sediment Provenance ◽  
Type I ◽  
Hydrocarbon Generation ◽  
Hydrocarbon Generation Potential ◽  
Primary Producer ◽  
Geochemical Analyses

The Upper Triassic Chang 9 organic-rich sediments have been considered as effective hydrocarbon source rocks for the Mesozoic petroleum system in the Ordos Basin. Previous studies on the Chang 9 member mostly focused on the influence of their paleoproductivity and paleoredox conditions on the organic matter (OM) enrichment, whereas there are few studies on the influence of the paleoclimate condition and sediment provenance on the OM enrichment. In this study, a series of geochemical analyses was performed on the Chang 9 core samples, and their hydrocarbon generation potential, paleoclimate condition, and sediment provenance were assessed to analyze the effect of paleoclimate-provenance on OM enrichment. The Chang 9 source rocks are characterized by high OM abundance, type I−II OM type, and suitable thermal maturity, implying good hydrocarbon generation potential. Based on the C-values and Sr/Cu ratios, the paleoclimate condition of the Chang 9 member was mainly semihumid. In addition, the Th/Co vs. La/Sc diagram and negative δEuN indicate that the Chang 9 sediments were mainly derived from felsic source rocks. Meanwhile, the paleoweathering intensity of the Chang 9 member is moderate based on moderate values of CIA, PIA, and CIW, which corresponds to the semihumid paleoclimate. The relatively humid paleoclimate not only enhances photosynthesis of the primary producer, but also promotes chemical weathering intensity, leading to suitable terrestrial clastic influx to the lacustrine basin, which is beneficial for OM enrichment.

scholarly journals Coupling between Source Rock and Reservoir of Shale Gas in Wufeng-Longmaxi Formation in Sichuan Basin, South China

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2679
Author(s):  
Yuying Zhang ◽  
Shu Jiang ◽  
Zhiliang He ◽  
Yuchao Li ◽  
Dianshi Xiao ◽  
...  
Keyword(s):  
Source Rock ◽  
Shale Gas ◽  
Sichuan Basin ◽  
Gas Content ◽  
Potential Zone ◽  
Hydrocarbon Generation ◽  
Gas Generation ◽  
Longmaxi Formation ◽  
Siliceous Shale ◽  
Organic Pores

In order to analyze the main factors controlling shale gas accumulation and to predict the potential zone for shale gas exploration, the heterogeneous characteristics of the source rock and reservoir of the Wufeng-Longmaxi Formation in Sichuan Basin were discussed in detail, based on the data of petrology, sedimentology, reservoir physical properties and gas content. On this basis, the effect of coupling between source rock and reservoir on shale gas generation and reservation has been analyzed. The Wufeng-Longmaxi Formation black shale in the Sichuan Basin has been divided into 5 types of lithofacies, i.e., carbonaceous siliceous shale, carbonaceous argillaceous shale, composite shale, silty shale, and argillaceous shale, and 4 types of sedimentary microfacies, i.e., carbonaceous siliceous deep shelf, carbonaceous argillaceous deep shelf, silty argillaceous shallow shelf, and argillaceous shallow shelf. The total organic carbon (TOC) content ranged from 0.5% to 6.0% (mean 2.54%), which gradually decreased vertically from the bottom to the top and was controlled by the oxygen content of the bottom water. Most of the organic matter was sapropel in a high-over thermal maturity. The shale reservoir of Wufeng-Longmaxi Formation was characterized by low porosity and low permeability. Pore types were mainly <10 nm organic pores, especially in the lower member of the Longmaxi Formation. The size of organic pores increased sharply in the upper member of the Longmaxi Formation. The volumes of methane adsorption were between 1.431 m3/t and 3.719 m3/t, and the total gas contents were between 0.44 m3/t and 5.19 m3/t, both of which gradually decreased from the bottom upwards. Shale with a high TOC content in the carbonaceous siliceous/argillaceous deep shelf is considered to have significant potential for hydrocarbon generation and storage capacity for gas preservation, providing favorable conditions of the source rock and reservoir for shale gas.

scholarly journals The characteristics of hydrocarbon generation, reserving performances of fine-grained rock, and preservation conditions of coal measure shale gas of an epicontinental sea basin: A case study of the Late Palaeozoic shale gas in the Huanghebei Area of Western Shandong

2018 ◽  
Vol 37 (1) ◽  
pp. 453-472 ◽  
Author(s):  
Ying Li ◽  
Zengxue Li ◽  
Huaihong Wang ◽  
Dongdong Wang
Keyword(s):  
Coal Seam ◽  
Shale Gas ◽  
Late Paleozoic ◽  
Organic Carbon Content ◽  
Hydrocarbon Generation ◽  
Average Content ◽  
Gas Generation ◽  
Geological Structures ◽  
Fine Grained ◽  
Western Shandong

In China, marine and land transitional fine-grained rocks (shale, mudstone, and so on) are widely distributed and are known to have large accumulated thicknesses. However, shale gas explorations of these types of rock have only recently been initiated, thus the research degree is very low. Therefore, this study was conducted in order to improve the research data regarding the gas accumulation theory of marine and continental transitional fine-grained rock, as well as investigate the shale gas generation potential in the Late Paleozoic fine-grained rock masses located in the Huanghebei Area of western Shandong Province. The hydrocarbon generation characteristics of the epicontinental sea coal measures were examined using sedimentology, petrography, geochemistry, oil and gas geology, tectonics, and combined experimental testing processes. The thick fine-grained rocks were found to have been deposited in the sedimentary environments of the tidal flats, barriers, lagoons, deltas, and rivers during the Late Paleozoic in the study area. The most typical fine-grained rocks were located between the No. 5 coal seam of the Shanxi Formation and the No. 10 coal seam of the Taiyuan Formation, with an average thickness of 84.8 m. These formations were mainly distributed in the western section of the Huanghebei Area. The total organic carbon content level of the fine-grained rock was determined to be 2.09% on average, and the higher content levels were located in the western section of the Huanghebei Area. The main organic matter types of the fine-grained rock were observed to be kerogen II, followed by kerogen III. The vitrinite reflectance ( Ro) of the fine-grained rock was between 0.72 and 1.25%, which indicated that the gas generation of the dark fine-grained rock was within a favorable range, and the maturity of the rock was mainly in a medium stage in the northern section of the Huanghebei Area. It was determined that the average content of brittle minerals in the fine-grained rock was 55.7%. The dissolution pores and micro-cracks were the dominating pores in the fine-grained rock, followed by intergranular pores and intercrystalline pores. It was also found that both the porosity and permeability of the fine-grained rock were very low in the study area. The desorption gas content of the fine-grained rock was determined to be between 0.986 and 4.328 m3/t, with an average content of 2.66 m3/t. The geological structures were observed to be simple in the western section of the Huanghebei Area, and the occurrence impacts on the shale gas were minimal. However, the geological structures were found be complex in the eastern section of the study area, which was unfavorable for shale gas storage. The depths of the fine-grained rock were between 414.05 and 1290.55 m and were observed to become increasingly deeper from the southwestern section to the northern section. Generally speaking, there were found to be good reservoir forming conditions and great resource potential for marine and continental transitional shale gas in the study area.

Study on the Forming Conditions of Shale Gas in Coal Measure of Wuli Area, Qinghai Province, China

2013 ◽  
Vol 295-298 ◽  
pp. 2770-2773 ◽  
Author(s):  
Dai Yong Cao ◽  
Jing Li ◽  
Ying Chun Wei ◽  
Xiao Yu Zhang ◽  
Chong Jing Wang
Keyword(s):  
Shale Gas ◽  
Thermal Evolution ◽  
Organic Matter Content ◽  
Gas Production ◽  
Matter Content ◽  
Source Rocks ◽  
Coal Measure ◽  
Gas Generation ◽  
Qinghai Province ◽  
Coal Measures

Besides coal seam, the source rocks including dark mudstone, carbon mudstone and so on account for a large proportion in the coal measures. Based on the complex geothermal evolution history, the majority of coal measure organic matters with the peak of gas generation have a good potential of gas. Therefore, shale gas in coal measure is an important part of the shale gas resources. There are good conditions including the thickness of coal measures, high proportion of shale rocks, rich in organic matter content, high degree of thermal evolution, high content of brittle mineral and good conditions of the porosity and permeability for the generation of shale gas in Wuli area, the south of Qinghai province. Also the direct evidence of the gas production has been obtained from the borehole. The evaluation of shale gas in coal measure resources could broaden the understanding of the shale gas resources and promote the comprehensive development of the coal resources.

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