Unconventional Hydrocarbon Resources Research Articles

Importance of Gas Hydrates for India and Characterization of Methane Gas Dissociation in the Krishna-Godavari Basin Reservoir

AbstractNatural gas hydrates are considered to be a strategic unconventional hydrocarbon resource in the Indian energy sector, and thermal stimulation is considered as one of the methods for producing methane from gas hydrate-bearing sediments. This paper discusses the importance of this abundantly available blue economic resource and analyzes the efficiency of methane gas production by circulating hot water in a horizontal well in the fine-grained, clay-rich natural gas hydrate reservoir in the Krishna-Godavari basin of India. Analysis is done using the electrothermal finite element analysis software MagNet-ThermNet and gas hydrate reservoir modeling software TOUGH+HYDRATE with reservoir petrophysical properties as inputs. Energy balance studies indicate that, in the 90% hydrate-saturated reservoir, the theoretical energy conversion ratio is 1:4.9, and for saturations below 20%, the ratio is <1. It is identified that a water flow of 0.2 m3/h at 270°C is required for every 1 m2 of wellhead surface area to dissociate gas hydrates up to a distance of 2.6 m from the well bore within 36 h.

Delineating property rights in unconventional hydrocarbon resources: Concepts from the United States and Germany

The use of hydraulic fracturing (fracking) and horizontal drilling technologies for recovering unconventional hydrocarbons (oil and gas) has created issues concerning the rights of property owners, energy companies, and others involved with the development and distribution of these resources. Constitutional provisions, legislative statutes, and jurisprudence on liability in the United States and Germany affect rights to oil and gas resources and the profitability of developing these resources. Legal rules for trespass, the rule of capture, pooling, unitization, and municipal fracturing bans circumscribe property rights associated with shale gas development in the United States. Germany, until setting up a specific, long-term legal regime on hydraulic fracturing, will rely on existing mining, water, and environmental legislation (as most recently modified). The evaluation of the law and jurisprudence governing unconventional hydrocarbon development in the U.S. and Germany discloses perceptions and expectations that contribute to widespread extraction in the U.S. while Germany contemplates the safety of allowing hydraulic fracturing.

Low Permeability Media: A Research Frontier

This thematic dossier collects eight scientific papers corresponding to presentations made during two international conferences dedicated to the study of low permeability media held in Paris within six months of each other. The first conference, “The Challenge of Studying Low Permeability Materials: Laboratory, in situ (field) and numerical methods”, was organised in December 2014 by the University of Cergy-Pontoise (Geosciences and Environment Cergy Research Laboratory) under the aegis of CFMR (Rock Mechanics French Committee) and GIS Geosciences franciliennes. The second, LowPerm2015 “Low permeability media and nanoporous materials from characterisation to modeling: Can we do it better?”, was organised by IFP Energies nouvelles in June 2015 under the aegis of the French “Academie des Sciences”. An attractive and explicit title is key to the success of a conference. It sets the scene and lets possible participants know exactly what matter will be discussed. But subtitles may be as important as titles, because they may stimulate participants by confronting them with a collective challenge. Devoted to characterisation, transport properties and multiscale modeling of low to very low permeability media and nanoporous materials, LowPerm2015 was leaving very little ambiguity about the matter to be discussed. Its subtitle – Can we do better? – was a mild way of stressing that there are several areas where we should be totally unsatisfied about our present state of knowledge, and where progress is urgently needed. One of these areas is the recovery of unconventional hydrocarbon resources. There is no question that the gas and oil shale revolution has deeply changed the global energy landscape, but its long term sustainability is questionable in spite of the tremendous magnitude of the resource due to an unacceptably low rate of recovery. With close to seventy five percent of the gas and ninety five percent of the oil left in place on average, the exploitation of self-sourced organic rich shale reservoirs is one of the least efficient industrial operations. Among the main reasons for this are our poor knowledge of the complex nanoporous void space in which the hydrocarbons are trapped, and our very limited understanding of their release and transport mechanisms, particularly in multiphase conditions. Just imagine what the future would be if, thanks to improved understanding, we could switch from ninety five percent left in place to ninety five percent recovery!

A systematic quality assessment of Environmental Impact Statements in the oil and gas industry

The global economy relies heavily on oil and gas resources. However, hydrocarbon exploitation projects can cause significant impacts on the environment. But despite the production of numerous Environmental Impact Statements (EISs) to identify/mitigate such impacts, no study has specifically assessed the quality of EISs for both onshore and offshore oil and gas projects, with tested hypotheses. To address this research gap, our paper, for the first time, develops a modified Lee and Colley evaluation model to assess the quality of 19 sampled oil and gas project EISs produced from 1998 to 2008 in Nigeria. Our findings show that Project Description and Communication of Results are the main areas of strength. However, Environmental Impact Prediction, and Project Decommissioning, were among the key areas requiring attention. A key finding, though, is that Mann-Whitney tests suggest that there is no evidence that the quality of EISs for the latter period (2004–2008) is higher than that of the earlier period (1998–2004). We suggest that periodic systematic review of the quality of submitted/approved EISs (c. every 3–5years) should be established to monitor trends in EIS quality and identify strong and weak areas. This would help to drive continual improvement in both the EIA processes and the resultant EISs of technical engineering projects. Such reviews have the potential to illuminate some of the underlying problems of, and solutions to, oil and gas exploration, production and transportation, and their related environmental impacts. This suggested change would also be useful internationally, including for the burgeoning exploration and production of unconventional hydrocarbon resources.

Observations on risks, the social sciences, and unconventional hydrocarbons

The activities employed in the development of unconventional hydrocarbon resources have been accompanied with health and environmental damages. To address the risks and damages from these activities, social scientists are probing probabilities of harm, estimating damages, and evaluating the ability of governmental regulators to arrest conduct causing damages. This lead article for a special issue on “Risks, the Social Sciences, and Unconventional Hydrocarbons” summarizes twenty papers to offer insights for developing policies to address future unconventional hydrocarbon development. Although economic, cultural, and political distinctions mean that people in different countries have diverse expectations on how their government should regulate energy development, the experiences reported by the papers of this special issue suggest that appropriate technology and governmental oversight can minimize adverse effects. Future research on the application and incorporation of ideas and knowledge into decisions and activities present challenges that call for innovative social science research to assist policy makers in meeting the challenges presented by the world's need for energy resources.

Upgrading of heavy oil by dispersed biogenic magnetite catalysts

In situ catalytic upgrading of heavy oil offers significant cost savings and overcomes logistical challenges associated with the high viscosity, low API gravity and high molecular weight fractions of unconventional hydrocarbon resources. The THAI-CAPRI process (toe-to-heel air injection – catalytic upgrading process in situ) offers one such route to upgrading through the use of high surface area transition metal cracking catalysts surrounding the production well. Here, we describe the catalytic upgrading of heavy oil in a stirred batch reactor by a biogenic nanoscale magnetite (BnM; Fe3O4). A 97.8% decrease in viscosity relative to the feed oil was achieved and coking was lower compared to thermal cracking alone (6.9wt% versus 10.2wt%). The activity of this catalyst was further enhanced by a simple one-step addition of surface associated Pd to achieve loadings of 4.3, 7.1 and 9.5wt% Pd. This led to significant decreases in viscosity of up to 99.4% for BnM loaded with 9.5wt% Pd. An increment of 7.8° in API gravity with respect to the feed oil was achieved for 9.5wt% Pd-BnM, compared with thermal cracking alone (5.3°). Whilst this level of upgrading was comparable to commercially available and previously tested catalysts, significant decreases in the coke content (3wt% for 9.5wt% Pd-BnM versus 10wt% for thermal cracking) and associated increases in liquid content (∼90wt% for 9.5wt% Pd-BnM versus ∼79wt% for thermal cracking) demonstrate the potential for the use of Pd-augmented biogenic magnetite as a catalyst in the THAI CAPRI process.

Research Progress in the Petroleum and Natural Gas Geological Theory of China

AbstractThe Chinese landmass, as a composite region, consists of multiple small continental blocks, such as Sino‐Korea, Yangtze, Tarim, etc., and orogenic belts. Because of its distinctive tectono‐sedimentary evolution, China's oil/gas‐bearing regions differ remarkably from that elsewhere in the world. For instance, in comparison to the Middle East oil/gas‐bearing regions which are characterized by Mesozoic‐Cenozoic marine oil/gas‐bearing beds, early oil and gas discoveries in China are distributed mainly in Mesozoic‐Cenozoic continental sedimentary basins. Generation of oil from terrestrial organic matter, or terrestrial oil generation, and the formation of large oil/gas fields in continental sedimentary basins were previously the major characteristics of petroleum geology of China. However, in the past 20 years, a series of major oil and gas discoveries from marine strata have been made. Marine oil/gas fields in China are mainly distributed in the Tarim, Sichuan, and Ordos basins, which are tectonically stable and covered with Mesozoic‐Cenozoic deposits. In these basins, hydrocarbon‐bearing strata are of old age and the oil/gas fields are commonly deeply‐buried. Cumulatively, 995 oil/gas fields have been found so far, making China the fourth largest oil‐producing country and the sixth largest gas‐producing country in the world. In terms of petroleum and natural gas geology, theories of hydrocarbon generation from continental strata, such as terrestrial oil generation and coal‐generated hydrocarbons, etc., have been established. Significant progress has been made in research on the sequence stratigraphy of continental strata, formation mechanisms of ultra‐deep clastic reservoirs, and hydrocarbon accumulation in the continental subtle reservoir. Regarding research on the marine petroleum geology of China, with respect to the major characteristics, such as deeply‐buried reservoirs, old strata, and multiple phases of transformation, important advances have been made, in areas such as the multiple‐elements of hydrocarbon supply, formation of reservoirs jointly controlled by deposition, tectonic activities, and diagenetic fluid‐rock reactions, and oil/gas reservoirs formed through superimposed multi‐stage hydrocarbon accumulation. As more and more unconventional hydrocarbon resources are discovered, unconventional oil and gas reservoirs are under study by Chinese petroleum geologists, who endeavor to come up with new discoveries on their formation mechanisms.

A new method for estimating total organic carbon content from well logs

With the booming exploration and development of unconventional hydrocarbon resources in source rocks, the estimation of total organic carbon (TOC) content from well logs has become increasingly important because of the significance of TOC in the formation evaluation of those resources. In this paper, a new log overlay method is developed to estimate the TOC content of source rocks with excess radioactivity, but containing little or no potassium feldspar. Specifically, on the basis of previous results of log responses of source rocks, it is believed that the natural gamma ray (GR) log responses of source rocks in the applicable conditions are predominantly contributed by clay minerals and organic matter. A practical clay indicator is established to reflect the clay content using density and neutron logs. The indicator is effective not only in nonsource rocks that contain oil or water but also in source rocks. Furthermore, a new method was developed by overlaying the properly scaled clay indicator curve on the GR curve. In nonsource rocks, including clay-rich rocks and reservoirs saturated with oil or water, the two curves overlie each other, whereas a separation between the curves occurs in organic-rich source rocks. The separation between the curves was defined and expressed and can be used to calculate the TOC consecutively after careful calibration with core data. This method has been successfully applied to two shale gas plays with high-maturity kerogen in the Sichuan Basin, China. In addition, a source rock with low-maturity kerogen was used to verify the new method for its effectiveness, reliability, and widespread adaptability.

Evaluating the characteristics of unconventional hydrocarbon resources with terahertz technology

太赫兹技术在石油领域展现出重要的应用价值, 尤其是针对油气储层潜能的表征与评价, 已在岩石矿物演化、地壳构造、孔隙结构、岩性、应力、各向异性、吸附动力学等方面取得了重要进展. 非常规油气资源储层富含纳米尺寸的分子和结构单元, 目前, 太赫兹技术在纳米尺度晶体管成像、粒子存在性探测、移动载流子分布等领域的突破, 为非常规油气资源的太赫兹波谱表征奠定了基础. 本文详细介绍了油气储层潜能太赫兹技术表征与评价的研究进展, 总结了近几年太赫兹波谱在微纳结构表征方面的技术突破, 最后提出了未来太赫兹技术在非常规油气资源领域的发展方向和面临的主要挑战.

Introduction to special section: Unconventional exploration and production — Achievements and remaining challenges

The time of “easy oil and gas from conventional plays” has passed. In recent decades, the oil and gas industry shifted its focus to unconventional hydrocarbon resources that now make up about two-thirds of the world’s oil and gas reserves. The well-known types of unconventional resources are

A constitutive model considering friction property of geomaterials and stability analysis of borehole

The strength and deformation properties of geomaterials are essential to estimating the cracking behavior of rock, especially for deep exploration of conventional and unconventional hydrocarbon resources. Because the geomaterials encountered in hydrocarbon exploration are generally granular friction materials formed from deposition or cementation of granular materials in natural conditions, they sustain loads by means of intergranular friction, which forms the main source of their shear strength. Therefore, the deformation and failure of friction material is governed by the friction law. A mechanical element of the friction material is modelled based on the concept that the internal friction exists in both the elastic state and the plastic state. By assuming that the friction coefficient is proportional to the strain, the friction stress is computed, and then the corresponding nonlinear elasto-plastic constitutive model of the friction material is established. Based on analysis of the internal friction effect of rock during macroscopic shear deformation, the mechanical mechanism of geomaterials' friction strength enhancement is explained. The nonlinear elasto-plastic constitutive model was used to compute the fracture and failure of a tunnel and a deep borehole. The results show that the model is effective for estimating the mechanical response of important geotechnical problems, such as the analysis of cracked rock-mass strength, forecasting crack closure, and borehole wall collapse.

Assessing the Extraction Potential of Tomsk Region’s Difficult-To-Obtain Oil Reserves

A significant increase in oil production in the Tomsk region can be achieved by a better development of the license areas at the disposal of oil-producing companies, active prospecting, introduction of innovative technologies to increase the oil recovery, as well as active oil extraction from unconventional horizons. This article reviews the activities of the oil-producing companies of the Tomsk region for the past 10 years, and proves the potential of increasing oil production of both traditional and difficult to obtain oil reserves, concentrated in the Bazhenov and Tyumen Formations and the Lower Jurassic sediments. Technologically, Russia is significantly lagging behind the economically developed countries in the extraction of hard unconventional hydrocarbon resources, primarily, the United States. The observed «shale revolution» was due to the complex of financial and tax breaks for oil companies, from which mainly medium and small companies were benefited. As a result, this requires an increase in investment on the part of economic entities and regional authorities, as well as additional tax benefits, considering the quality and types of actual and prospective raw materials produced in the region, in contrast to the declared benefits in Eastern Siberia. The introduction of tax incentives justified by the authors and the implementation of public-private partnership will ensure the profitability of the development of marginal and difficult-to-obtain oil deposits of the Tomsk region in the long term, which in turn should ensure the stability of economic development of the subject of the Russian Federation.

비전통 탄화수소 자원의 지질학적 의의

비전통 탄화수소 자원의 지질학적 의의

Use of borehole imaging to improve understanding of the in-situ stress orientation of Central and Northern England and its implications for unconventional hydrocarbon resources

New interest in the potential for shale gas in the United Kingdom (UK) has led to renewed exploration for hydrocarbons in the Carboniferous age Bowland–Hodder shales under Central and Northern England. Following an incidence of induced seismicity from hydraulic fracturing during 2010 at Preese Hall, Lancashire, the publically available databases quantifying the in-situ stress orientation of the United Kingdom have shown to be inadequate for safe planning and regulation of hydraulic fracturing. This paper therefore reappraises the in-situ stress orientation for central and northern England based wholly on new interpretations of high-resolution borehole imaging for stress indicators including borehole breakouts and drilling-induced tensile fractures. These analyses confirm the expected north northwest – south southeast orientation of maximum horizontal in-situ stress identified from previous studies (e.g. Evans and Brereton, 1990). The dual-caliper data generated by Evans and Brereton (1990) yields a mean SHmax orientation of 149.87° with a circular standard deviation of 66.9°. However the use of borehole imaging without incorporation of results from older dual-caliper logging tools very significantly decreases the associated uncertainty with a mean SHmax orientation of 150.9° with a circular standard deviation of 13.1°.The use of high-resolution borehole imaging is thus shown to produce a more reliable assessment of in-situ stress orientation. The authors therefore recommend that the higher resolution of such imaging tools should therefore be treated as a de-facto standard for assessment of in-situ stress orientation prior to rock testing. Use of borehole imaging should be formally instituted into best practice or future regulations for assessment of in-situ stress orientation prior to any hydraulic fracturing operations in the UK.

Assessment of hard-to-recover oil reserves production potential in Tomsk region

The development of the licensed areas, profound geological exploration, enhanced oil recovery due to innovative technologies introduction and revitalization of oil production from unconventional horizons could significantly increase the oil production in the Tomsk region. This article deals with the issue of oil producing companies’ affairs of the Tomsk region for the past 10 years and proves the oil production potential growth through the development of both conventional and hard-to-recover unconventional oil reserves, concentrated in the Bazhenov and Tyumen Formations, as well as in the Lower Jurassic sediments. The Russian Federation is far behind from the economically developed countries, especially from the United States, in the exploitation of hard-to-recover unconventional hydrocarbon resources. The «shale revolution» was determined by a complex of financial and tax incentives introduced for oil and gas companies. However, this was mainly beneficial for medium and small sized companies. Therefore, both the business entities and regional authorities should increase the investments spending, as well as introduce the additional tax incentives considering the quality and type of potentially available raw hydrocarbons produced in the region, in contrast to the declared benefits in the territory of Eastern Siberia. The introduction of tax incentives justified by the authors, and the implementation of public-private partnership mechanism will ensure the profitability of marginal and hard-to-recover deposits development of the Tomsk region in the long run, which in its turn, should ensure the stability of the economic development of the reviewed subject of the Russian Federation.

Tight sandstone gas accumulation mechanism and development models

Tight sandstone gas serves as an important unconventional hydrocarbon resource, and outstanding results have been obtained through its discovery both in China and abroad given its great resource potential. However, heated debates and gaps still remain regarding classification standards of tight sandstone gas, and critical controlling factors, accumulation mechanisms, and development modes of tight sandstone reservoirs are not determined . Tight sandstone gas reservoirs in China are generally characterized by tight strata, widespread distribution areas, coal strata supplying gas, complex gas–water relations, and abnormally low gas reservoir pressure. Water and gas reversal patterns have been detected via glass tube and quartz sand modeling, and the presence of critical geological conditions without buoyancy-driven mechanisms can thus be assumed. According to the timing of gas charging and reservoir tightening phases, the following three tight sandstone gas reservoir types have been identified: (a) “accumulation–densification” (AD), or the conventional tight type, (b) “densification–accumulation” (DA), or the deep tight type, and (c) the composite tight type. For the AD type, gas charging occurs prior to reservoir densification, accumulating in higher positions under buoyancy-controlled mechanisms with critical controlling factors such as source kitchens (S), regional overlaying cap rocks (C), gas reservoirs, (D) and low fluid potential areas (P). For the DA type, reservoir densification prior to the gas charging period (GCP) leads to accumulation in depressions and slopes largely due to hydrocarbon expansive forces without buoyancy, and critical controlling factors are effective source rocks (S), widely distributed reservoirs (D), stable tectonic settings (W) and universal densification of reservoirs (L). The composite type includes features of the AD type and DA type, and before and after reservoir densification period (RDP), gas charging and accumulation is controlled by early buoyancy and later molecular expansive force respectively. It is widely distributed in anticlinal zones, deep sag areas and slopes, and is controlled by source kitchens (S), reservoirs (D), cap rocks (C), stable tectonic settings (W), low fluid potential areas (P), and universal reservoir densification (L). Tight gas resources with great resource potential are widely distributed worldwide, and tight gas in China that presents advantageous reservoir-forming conditions is primarily found in the Ordos, Sichuan, Tarim, Junggar, and Turpan-Hami basins of central-western China. Tight gas has served as the primary impetus for global unconventional natural gas exploration and production under existing technical conditions.

The concept and the accumulation characteristics of unconventional hydrocarbon resources

Unconventional hydrocarbon resources, which are only marginally economically explored and developed by traditional methods and techniques, are different from conventional hydrocarbon resources in their accumulation mechanisms, occurrence states, distribution models, and exploration and development manners. The types of unconventional hydrocarbon are controlled by the evolution of the source rocks and the combinations of different types of unconventional reservoirs. The fundamental distinction between unconventional hydrocarbon resources and conventional hydrocarbon resources is their non-buoyancy-driven migration. The development of the micro- to nano-scale pores results in rather high capillary resistance. The accumulation mechanisms of the unconventional and the conventional hydrocarbon resources are also greatly different. In conventional hydrocarbon resources, oil and gas entrapment is controlled by reservoir-forming factors and geological events, which is a dynamic balance process; while for unconventional hydrocarbon resources, the gas content is affected by the temperature and pressure fields, and their preservation is crucial. Unconventional and conventional hydrocarbons are distributed in an orderly manner in subsurface space, having three distribution models of intra-source rock, basin-centered, and source rock interlayer. These results will be of great significance to unconventional hydrocarbon exploration.

Anatomy of a basin-controlled foreland fold-thrust belt curve: The Três Marias salient, São Francisco basin, Brazil

Salients, as common features of fold-thrust belts, correspond to convex-to-foreland map-view curves. Hosting sedimentary sequences younger than 1,8 Ga., the intracratonic São Francisco basin of southeastern Brazil encompasses two foreland fold-thrust belts of opposite vergences: the Brasília, on the west, and the Araçuaí, on the east. These belts culminate in the central portion of the basin in form of two almost touching antitaxial curves developed in response to diachronic orogenic events affecting the basin fill-units during the Ediacaran Brasiliano/Pan-African assembly of West Gondwana. Located in the external sector of the thin-skinned Brasília foreland fold-thrust belt, the ca. 130 km long and 80 km wide Três Marias salient involves the up to 2500 m-thick Ediacaran Bambuí sequence. In order to characterize the overall architecture and processes involved in the generation of the Três Marias salient, we conducted a detailed structural investigation of the southern segment of the Brasília foreland fold-thrust belt, based on surface, seismic, well and aerogeophysical data interpretation. The salient is frankly dominated by monotonous trains of upright chevron folds, bounded by a small number west-dipping thrust faults. The structural traces of thrusts and fold hinges on maps trend preferentially NS in the central portion of the salient, curving progressively toward NE and NW in its southern and northern limbs, respectively. The entire system is linked to a spoon-shaped detachment zone located near the base of the Ediacaran Bambuí strata, whose maximum thickness roughly coincides with the salient culmination. Our analysis led to the conclusion that the Três Marias salient corresponds to a basin-controlled curve, generated during a single and progressive deformational episode. Its fold-dominated character and the high symmetry of its internal fabrics can be explained by the low friction of the associated detachment (located along a lower Bambuí sequence black shale) and the mechanical behavior of the pelite-dominated deposits incorporated in the fold-thrust wedge. The occurrence of seepages and recent gas discoveries in the Três Marias salient area point toward its potential for unconventional hydrocarbon resources. Our investigation suggests that the main basin controls that led to the development of the salient might have controlled the quality and distribution of Proterozoic petroleum system elements.

Chapter 11 Unconventional hydrocarbon resources in Myanmar

Unconventional resources comprise shale gas, shale oil, coal-bed methane, tight gas/oil sands and heavy oil. There is currently no commercial exploitation of unconventional hydrocarbon resources in Myanmar and this side of the industry is very much in its infancy; see Table 11.1 for a summary. View this table: Table 11.1. Unconventional resource potential (from Lynn Myint 2014) Gas shales are thermally mature, organic-rich, source rocks in which gas is held in natural fractures within some pore spaces and also adsorbed onto the organic material. Areas of focus comprise the Tertiary in the Hukaung, Chindwin, Salin, Pyay, Ayeyarwady, Shwebo-Monywa, Myitkyina-Katha, Bago Yoma and Sittaung basins or areas and the Silurian–Devonian in the Lashio and Kalaw areas (Northern Shan State). The best studied of these is the western flank of the Sailin Basin where the source parameters shown in Table 11.2 are noted (after Lynn …

Organic geochemistry and petrology of Lower Cretaceous black shales in the Qiangtang Basin, Tibet: Implications for hydrocarbon potential

Lower Cretaceous black shales have recently been discovered in the Qiangtang Basin (especially in its northern basin), Tibet, implying a new interval with hydrocarbon resource potential in the region. This potential, however, has not been investigated to date and is addressed in this paper based on organic petrology and geochemistry data from the representative Shengli River outcrop. Organic petrology, including optical and scanning electron microscope observations, indicates that the organic matter (OM) within these shale sequences has precursors from abundant benthic algae, some bacteria and amorphous OM and a few land plants, suggesting that the black shales were deposited in a generally reducing platform–lagoonal environment favorable for OM preservation. The shales have high total organic carbon (TOC) contents (1.74–7.71wt%), type II kerogen (tending to type III), and high thermal maturity (vitrinite reflectance equivalent of ca. 1.3 %Ro). Biomarkers in the shales suggest deposition under reducing brackish or saline water with aquatic benthic organisms, bacteria and amorphous OM as the dominant input. Thus, the results of organic petrology, organic geochemistry and biomarker geochemistry are generally consistent and imply that the Shengli River black shale samples have significant hydrocarbon resource potential and most likely produced gas due to relatively high maturity and gas-prone kerogen. The neighboring black shales within the same stratigraphic interval as the Shengli River shales, if having moderate OM maturity and oil-prone kerogen, can be expected to generate oil. The presence of well-developed micropores and fractures, and abundant brittle minerals within the black shales suggests that they may have unconventional hydrocarbon resource potential, especially in intervals with high TOC>4.0wt%. These results provide new data and understanding for regional hydrocarbon exploration.