Lithofacies-dependent rock physics templates of an unconventional shale reservoir on the North Slope, Alaska

2020 ◽  
pp. 1-49
Author(s):  
Minh Tran ◽  
Tapan Mukerji ◽  
Allegra Hosford Scheirer
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Source Rock ◽  
Velocity Ratio ◽  
Rock Physics ◽  
Hydrogen Index ◽  
Source Rocks ◽  
Rock Properties ◽  
North Slope ◽  
Petrophysical Properties

Over the past 20 years, oil and gas companies have turned their attention to producing petroleum directly from organic-rich shale. Successful exploration, appraisal, and production strategies for source rocks critically depend on reliable identification of their organic components (kerogen, in particular) and generation potential. There is mounting demand to evaluate organic richness in terms of quantity (i.e. total organic carbon) and quality (i.e. hydrogen index) from seismic data, which is usually the only source of information in the early development period of emerging shale plays. We delineated major seismic lithofacies on the Alaska North Slope using elastic, seismic, and petrophysical properties. We performed a well-established quantitative seismic interpretation workflow to integrate geochemical data in the lithofacies definition. Rock physics templates of seismic parameters, Acoustic Impedance, (AI), versus P-wave to S-wave velocity ratio, (VP/VS), are constructed for each lithofacies to assess variations in pore fluid and lithology. We proposed correlations between source rock properties (hydrogen index, total organic carbon) and petrophysical properties (bulk density, porosity, sonic velocity ratio) of the major lithofacies. These correlations, together with facies-specific rock physics templates, can be utilized to predict organic richness and source rock properties away from drilled wells. The models are validated by training data from 2 regional wells to observe their applicability on the Alaska North Slope.

scholarly journals Hydrocarbon source rock evaluation of the Lower Cretaceous system in the Baibei Depression, Erlian Basin

2017 ◽  
Vol 36 (3) ◽  
pp. 355-372 ◽  
Author(s):  
Hua Liu ◽  
Jinglun Ren ◽  
Jianfei Lyu ◽  
Xueying Lyu ◽  
Yuelin Feng
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Source Rock ◽  
Lower Cretaceous ◽  
Vitrinite Reflectance ◽  
Source Rocks ◽  
Main Stage ◽  
Type I ◽  
Potential Source Rock ◽  
Erlian Basin

The K1s, K1d, K1t, and K1a Formations are potential source rock intervals for hydrocarbon formation, all of which are part of the Lower Cretaceous system in the Baibei Depression in the Erlian Basin in China. However, no well has found oil flow because the hydrocarbon-generating potential of the source rocks has not been comprehensively evaluated. Based on organic geochemical and petrological analyses, all the source rocks possess highly variable total organic carbon and S1 + S2 contents. Total organic carbon and S1 + S2 contents indicate that the K1a2 Formation through the K1d1 Formation are source rocks that have fair to good generative potential and the K1d2 Formation through the K1s Formation are source rocks that have good to very good generative potential. The organic matter in the K1a2 Formation is dominated by Type I and II kerogen; thus, it is considered to be oil prone based on H/C versus O/C plots. Most of the analyzed samples were deposited in reducing environments and sourced from marine algae; thus, they are oil prone. However, only two source rock intervals were thermally mature with vitrinite reflectance values in the required range. Hydrocarbon-generating histories show that the K1t and K1a2 intervals began to generate hydrocarbons during the depositional period of the K1d2 and K1d3 Formations, respectively, and stopped generating hydrocarbons at the end of the depositional period of the late Cretaceous. Therefore, the main stage of hydrocarbon migration and accumulation was between the depositional period of the K1d2 and K1s Formations, and the critical moment was the depositional period of the late K1s Formation. The generation conversion efficiency reached approximately 55% in the K1a2 Formation and 18% in the K1t Formation at the end of the Cretaceous sedimentary stage. In general, the effective oil traps are those reservoirs that are near the active source rock in the generating sags in the Baibei Depression.

scholarly journals The Lithofacies of Pandua Formation Shale in the Andowia Area, North Konawe, Southeast Sulawesi and Its potential as Petroleum source rock

2021 ◽  
Vol 325 ◽  
pp. 08013
Author(s):  
Mawar Towan Lestari Ramli ◽  
Hendra Amijaya ◽  
Akmaluddin
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Source Rock ◽  
Depositional Environment ◽  
Petrographic Analysis ◽  
Hydrocarbon Accumulation ◽  
High Concentration ◽  
Area North ◽  
Excellent Source ◽  
Petroleum Source Rock

Research on the Late Miocene of Pandua Formation shale in Andowia area, Southeast Sulawesi is fundamental because it is considered to have the potential as a source rock in Manui Basin. This study aimed to determine the lithofacies and its potential as petroleum source rock using megascopic, petrographic, and total organic carbon analyses in Pandua Formation shale. Based on the megascopic and petrographic analysis of outcrops, the shale can be subdivided into 11 lithofacies consists of clayey shale, massive claystone, clastic detritus-rich claystone, massive mudstone, mica-rich mudstone, iron oxide-rich mudstone, low-angle laminated mudstone, massive siltstone, carbon-rich massive siltstone, laminated siltstone, and carbon-rich laminated siltstone. The results of the analysis of 19 samples of shale showed that the total organic carbon (TOC) content was classified as poor to excellent (<0.5%- >4%). The lithofacies with a high concentration of TOC are carbon-rich massive siltstone and carbon-rich laminated siltstone. Both lithofacies were categorized as potentially excellent source rock which the TOC value content is 5.78% and 5.74%.The result implies the better understanding of the depositional environment and hydrocarbon accumulation potential of the Manui basin for future exploration.

scholarly journals GEOKIMIA BATUAN INDUK HIDROKARBON FORMASI CINAMBO DI DAERAH SUMEDANG, JAWA BARAT

2017 ◽  
Vol 12 (3) ◽  
pp. 144-153
Author(s):  
Praptisih Praptisih
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Hydrogen Index ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Rock Eval

Penelitian geokimia batulempung telah dilakukan pada Formasi Cinambo di wilayah Kabupaten Sumedang, dengan tujuan untuk mengetahui karakter batuan induk dan biomarker ekstrak batuan serta hubungannya dengan rembesan minyak di daerah Majalengka. Metode yang dilakukan adalah penelitian lapangan dan analisis laboratorium yang meliputi analisis Total Organic Carbon (TOC), pirolisis Rock Eval dan Gas Chromatography Mass Spectrometry (GCMS). Penelitian lapangan meliputi pengamatan litostratigrafi Formasi Cinambo pada Sungai Cinambo dan Cisaar serta pengambilan  percontoh untuk analisis laboratorium. Hasil analisis dari 16 percontoh batulempung Formasi Cinambo menunjukkan nilai TOC 0,32-1,47% yang berpotensi rendah hingga baik untuk membentuk hidrokarbon. Material organik di daerah penelitian termasuk dalam kerogen tipe III, berdasarkan diagram TOC vs Hydrogen Index (HI). Tingkat kematangan 4 percontoh mengindikasikan kondisi belum matang (immature), 6 percontoh termasuk matang dan 6 percontoh lainnya tidak terdeteksi. Berdasarkan nilai HI, yaitu 2-90, dapat menghasilkan gas dengan kuantitas kecil. Hasil biomarker ekstrak batuan Formasi Cinambo menunjukkan tidak ada korelasi positif dengan rembesan minyak di daerah Majalengka.

scholarly journals Total Organic Carbon (TOC) Value Prediction in Source Rock Potential at North East Java Basin, Indonesia

2021 ◽  
Vol 6 (3) ◽  
pp. 147-151
Author(s):  
Paulus Leonardo Manurung ◽  
Rahmat Catur Wibowo ◽  
Ordas Dewanto
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Source Rock ◽  
Vitrinite Reflectance ◽  
Excellent Quality ◽  
North East ◽  
The North ◽  
Sonic Log ◽  
Maturity Variable ◽  
Resistivity Log

This research aims to determine the potential of the source rock in the Kujung and Cepu Formations in the North East Java Basin, using Total Organic Carbon (TOC). TOC is calculated using the Passey method. The Passey method is used by overlaying the sonic log and the resistivity log and determining the baseline to get the separation of Δlog resistivity, which is then used to predict the TOC log by including the LOM (Level of Organic Maturity) variable obtained from the data of vitrinite reflectance. After the TOC log value is obtained, a correlation is made with the TOC core value. The prediction result of TOC log in a PM-1 well is 2.16%, which means it has excellent quality. The prediction of TOC log in a PM-2 well is worth 2.68%, which means it has excellent quality. The correlation value between the TOC log and the TOC core of the PM-1 well is 0.67, which means the correlation is strong. In PM-2 well, the correlation between the TOC log and TOC core is 0.92, which means that the correlation is robust.

scholarly journals A New Evaluation Method of Total Organic Carbon for Shale Source Rock Based on the Effective Medium Conductivity Theory

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jian Fu ◽  
Xuesong Li ◽  
Yonghe Sun ◽  
Qiuli Huo ◽  
Ting Gao ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Clay Minerals ◽  
Pore Water ◽  
Effective Medium ◽  
Source Rocks ◽  
Model Parameters ◽  
Hydrocarbon Generation ◽  
Tight Sandstone

In the evaluation of source rocks, the total organic carbon (TOC) is an important indicator to evaluate the hydrocarbon generation potential of source rocks. At present, the commonly used methods for assessing TOC include △ log R and neural network method. However, practice shows that these methods have limitations in the application of unconventional intervals of sand-shale interbeds, and they cannot sufficiently reflect the variation of TOC in the vertical direction. Therefore, a total organic carbon (TOC) evaluation model suitable for shale and tight sandstone was established based on the effective medium symmetrical conduction theory. The model consists of four components: nonconductive matrix particles, clay minerals, organic components (solid organic matter and hydrocarbons), and pore water. The conductive phase in the model includes clay minerals and pore water, and other components are treated as nonconductive phases. When describing the conductivity of rock, each component in the model is completely symmetrical, and anisotropic characteristics of each component are considered. The model parameters are determined through the optimization method, and the bisection iteration method is used to solve the model equation. Compared with the classic TOC calculation method, the new model can evaluate the abundance of organic matter in shale and tight sandstone, which provides a new option to assess the TOC of rocks based on logging methods.

Evaluation of the total organic carbon of source rocks in lacustrine basins using the variable-coefficient ΔLgR technique — A case study of the Xujiaweizi Fault Depression in the Songliao Basin

2019 ◽  
Vol 7 (4) ◽  
pp. SJ67-SJ75
Author(s):  
Chao Liu ◽  
Lidong Sun ◽  
Jijun Li ◽  
Shuangfang Lu ◽  
Lei Tian ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Variable Coefficient ◽  
Prediction Equation ◽  
Songliao Basin ◽  
Source Rocks ◽  
High Quality ◽  
Natural Gamma ◽  
The Individual ◽  
Fourth Member

To lay the foundation for the exploration of shale gas, we calculated the total organic carbon (TOC) of Shahezi Formation source rocks in the Xujiaweizi Fault Depression in the Songliao Basin by using the measuring data and the logging curves. Because the source rocks in the study area were formed in a lacustrine basin, they are characterized by strong organic heterogeneity, making it difficult to objectively characterize any changes in the TOC of the underground source rocks based on discrete and limited sampling. In addition, because the source rock is relatively rich in shale and poor in organic matter, the logging response features of high natural gamma, medium-high interval transit time, and medium-low resistivity, making it easily identified. However, because the logging parameters to predict the TOC of source rocks are not universal, it is impossible to establish a prediction equation that is universally applicable. To solve the above problems, we used the variable-coefficient [Formula: see text] technique to predict the TOC of the source rocks in the study area. We defined the two key parameters that affect the TOC prediction in the classic [Formula: see text] technique as the undetermined coefficients, and the coefficients were determined according to the logging and geologic data of the individual wells. The application results indicate that the variable-coefficient [Formula: see text] technique has an average relative error of 17.5% in the prediction of the TOC, which is 16.1% lower than that of the classic [Formula: see text] technique. Thus, the prediction results can effectively reflect the vertical variation in the TOC of source rocks. Based on the logging evaluation results for the TOC of source rocks in 35 wells throughout the study area, the thickness of the high-quality source rocks in the fourth member of the Shahezi Formation was mapped. The thickness of the high-quality source rocks in the fourth member of the Shahezi Formation is generally [Formula: see text]. There are two centers of greater thickness in the plane, with the maximum thickness of more than 70 m.

scholarly journals 3D-Basin Modelling of the Lishui Sag: Research of Hydrocarbon Potential, Petroleum Generation and Migration

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 650 ◽  
Author(s):  
Jinliang Zhang ◽  
Jiaqi Guo ◽  
Jinshui Liu ◽  
Wenlong Shen ◽  
Na Li ◽  
...  
Keyword(s):  
Source Rock ◽  
Thermal Evolution ◽  
Vitrinite Reflectance ◽  
Three Dimensional ◽  
Source Rocks ◽  
Rock Properties ◽  
Hydrocarbon Generation ◽  
Hydrocarbon Accumulation ◽  
Southeastern Part ◽  
Petroleum Generation

The Lishui Sag is located in the southeastern part of the Taibei Depression, in the East China Sea basin, where the sag is the major hydrocarbon accumulation zone. A three dimensional modelling approach was used to estimate the mass of petroleum generation and accumulated during the evolution of the basin. Calibration of the model, based on measured maturity (vitrinite reflectance) and borehole temperatures, took into consideration two main periods of erosion events: a late Cretaceous to early Paleocene event, and an Oligocene erosion event. The maturation histories of the main source rock formations were reconstructed and show that the peak maturities have been reached in the west central part of the basin. Our study included source rock analysis, measurement of fluid inclusion homogenization temperatures, and basin history modelling to define the source rock properties, the thermal evolution and hydrocarbon generation history, and possible hydrocarbon accumulation processes in the Lishui Sag. The study found that the main hydrocarbon source for the Lishui Sag are argillaceous source rocks in the Yueguifeng Formation. The hydrocarbon generation period lasted from 58 Ma to 32 Ma. The first period of hydrocarbon accumulation lasted from 51.8 Ma to 32 Ma, and the second period lasted from 23 Ma to the present. The accumulation zones mainly located in the structural high and lithologic-fault screened reservoir filling with the hydrocarbon migrated from the deep sag in the south west direction.

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