Interpretation of fractures and joint inversion using multicomponent seismic data — Marcellus Shale example

2014 ◽  
Vol 2 (2) ◽  
pp. SE55-SE62 ◽  
Author(s):  
Shukun Yuan ◽  
Michael V. DeAngelo ◽  
Bob A. Hardage
Keyword(s):  
Shale Gas ◽  
Oil And Gas ◽  
Reservoir Characterization ◽  
Joint Inversion ◽  
Marcellus Shale ◽  
Natural Fracture ◽  
Gas Reservoirs ◽  
Horizontal Drilling ◽  
Multicomponent Seismic ◽  
Shale Gas Reservoirs

Evaluating and exploiting unconventional complex oil and gas reservoirs such as the Marcellus Shale gas reservoirs within the Appalachian Basin in Pennsylvania, USA, have gained considerable interest in recent years. Technologies such as conventional 3D seismic, horizontal drilling, and hydraulic fracturing have been at the forefront of the effort to exploit these resources. Recently, multicomponent seismic technologies have been integrated into some resource evaluation and reservoir characterization activities of low-permeability rock systems. We evaluated how multicomponent seismic technology provides value to reservoir characterization in shale gas exploration. We improved fault interpretations and natural fracture identifications by means of [Formula: see text] and [Formula: see text] integrated interpretation. In addition, using P-P-/P-SV-joint inversion, we extracted key parameters, such as [Formula: see text] ratio and density, that improve stratigraphic interpretation and rock-property descriptions of shale gas reservoirs.

Modeling Gas Adsorption in Marcellus Shale With Langmuir and BET Isotherms

SPE Journal ◽  
2016 ◽  
Vol 21 (02) ◽  
pp. 589-600 ◽  
Author(s):  
Wei Yu ◽  
Kamy Sepehrnoori ◽  
Tadeusz W. Patzek
Keyword(s):  
Shale Gas ◽  
Langmuir Isotherm ◽  
History Matching ◽  
Gas Adsorption ◽  
Marcellus Shale ◽  
Methane Adsorption ◽  
Gas Reservoirs ◽  
Gas Desorption ◽  
Shale Gas Reservoirs ◽  
Bet Isotherm

Summary Production from shale-gas reservoirs plays an important role in natural-gas supply in the United States. Horizontal drilling and multistage hydraulic fracturing are the two key enabling technologies for the economic development of these shale-gas reservoirs. It is believed that gas in shale reservoirs is mainly composed of free gas within fractures and pores and adsorbed gas in organic matter (kerogen). It is generally assumed in the literature that the monolayer Langmuir isotherm describes gas-adsorption behavior in shale-gas reservoirs. However, in this work, we analyzed four experimental measurements of methane adsorption from the Marcellus Shale core samples that deviate from the Langmuir isotherm, but obey the Brunauer-Emmett-Teller (BET) isotherm. To the best of our knowledge, it is the first time to find that methane adsorption in a shale-gas reservoir behaves similar to multilayer adsorption. Consequently, investigation of this specific gas-desorption effect is important for accurate evaluation of well performance and completion effectiveness in shale-gas reservoirs on the basis of the BET isotherm. The difference in calculating original gas in place (OGIP) on the basis of both isotherms is discussed. We also performed history matching with one production well from the Marcellus Shale and evaluated the contribution of gas desorption to the well's performance. History matching shows that gas adsorption obeying the BET isotherm contributes more to overall gas recovery than gas adsorption obeying the Langmuir isotherm, especially at early time in production. This work provides better understanding of gas desorption in shale-gas reservoirs and updates our current analytical and numerical models for simulation of shale-gas production.

scholarly journals Shale Gas Reservoirs Characterization: Marcellus Shale and Brazilian Potential

2015 ◽  
Vol 17 (2) ◽  
Author(s):  
Pamela Cardoso Vilela ◽  
Alexandre de Castro Leiras Gomes
Keyword(s):  
Shale Gas ◽  
Marcellus Shale ◽  
Gas Reservoirs ◽  
Shale Gas Reservoirs

scholarly journals A Workflow for Integrated Geological Modeling for Shale Gas Reservoirs: A Case Study of the Fuling Shale Gas Reservoir in the Sichuan Basin, China

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Xiaofei Shang ◽  
Huawei Zhao ◽  
Shengxiang Long ◽  
Taizhong Duan
Keyword(s):  
Shale Gas ◽  
Production Optimization ◽  
Natural Fracture ◽  
Geological Modeling ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Shale Gas Reservoir ◽  
Shale Gas Reservoirs ◽  
Stratigraphic Model

Shale gas reservoir evaluation and production optimization both require geological models. However, currently, shale gas modeling remains relatively conventional and does not reflect the unique characteristics of shale gas reservoirs. Based on a case study of the Fuling shale gas reservoir in China, an integrated geological modeling workflow for shale gas reservoirs is proposed to facilitate its popularization and application and well improved quality and comparability. This workflow involves four types of models: a structure-stratigraphic model, reservoir (matrix) parameter model, natural fracture (NF) model, and hydraulic fracture (HF) model. The modeling strategies used for the four types of models vary due to the uniqueness of shale gas reservoirs. A horizontal-well lithofacies sublayer calibration-based method is employed to build the structure-stratigraphic model. The key to building the reservoir parameter model lies in the joint characterization of shale gas “sweet spots.” The NF models are built at various scales using various methods. Based on the NF models, the HF models are built by extended simulation and microseismic inversion. In the entire workflow, various types of models are built in a certain sequence and mutually constrain one another. In addition, the workflow contains and effectively integrates multisource data. Moreover, the workflow involves multiple model integration processes, which is the key to model quality. The selection and optimization of modeling methods, the innovation and development of modeling algorithms, and the evaluation techniques for model uncertainty are areas where breakthroughs may be possible in the geological modeling of shale gas reservoirs. The workflow allows the complex process of geological modeling of shale gas reservoirs to be more systematic. It is of great significance for a dynamic analysis of reservoir development, from individual wells to the entire gas field, and for optimizing both development schemes and production systems.

Petrophysical Evaluation of Shale Gas Reservoirs: A Field Case Study of Marcellus Shale

2019 ◽  
Author(s):  
Levent Taylan Ozgur Yildirim ◽  
John Yilin Wang ◽  
Derek Elsworth
Keyword(s):  
Shale Gas ◽  
Marcellus Shale ◽  
Gas Reservoirs ◽  
Field Case ◽  
Shale Gas Reservoirs ◽  
Petrophysical Evaluation

Factors Affecting Hydraulically Fractured Well Performance in the Marcellus Shale Gas Reservoirs

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Tunde Osholake ◽  
John Yilin Wang ◽  
Turgay Ertekin
Keyword(s):  
Hydraulic Fracturing ◽  
Shale Gas ◽  
Marcellus Shale ◽  
Operating Conditions ◽  
Gas Reservoirs ◽  
Factors Affecting ◽  
Reservoir Compaction ◽  
Multistage Hydraulic Fracturing ◽  
Shale Gas Reservoirs ◽  
Fracturing Process

Development of shale gas reservoirs has become an integral part of the North American gas supply. The Marcellus shale reservoir contains large untapped natural gas resources and its proximity to high demand markets along the East Coast of the United State makes it an attractive target for energy development. The economic viability of such unconventional gas development hinges on the effective stimulation of extremely low permeability reservoir rocks. Horizontal wells with multistage hydraulic fracturing technique are the stimulation method of choice and have been successful in shale gas reservoirs. However, the fundamental science and engineering of the process are yet to be fully understood and hence the protocol that needs to be followed in the stimulation process needs to be optimized. There are several factors affecting the hydraulic fracture treatment and the postfracture gas production in shale gas reservoirs. In this paper, we used numerical reservoir simulation techniques and quantified the effect of the following pertinent factors: multiphase flow, proppant crushing, proppant diagenesis, reservoir compaction, and operating conditions on the performance of the designed multistage hydraulic fracturing process. The knowledge generated in this study is expected to enable engineers to better design fracture treatments and operators to better manage the wells in the Marcellus shale gas reservoir.

scholarly journals A Comprehensive Model for Estimating Stimulated Reservoir Volume Based on Flowback Data in Shale Gas Reservoirs

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Qi Chen ◽  
Shaojun Wang ◽  
Dan Zhu ◽  
Guoxuan Ren ◽  
Yuan Zhang ◽  
...  
Keyword(s):  
Relative Permeability ◽  
Shale Gas ◽  
Stress Sensitivity ◽  
Comprehensive Model ◽  
Gas Reservoirs ◽  
Horizontal Drilling ◽  
Stimulated Reservoir Volume ◽  
Reservoir Volume ◽  
Microseismic Data ◽  
Shale Gas Reservoirs

Stimulated reservoir volume (SRV) which is generated by horizontal drilling with multistage hydraulic fracturing governs the production in the shale gas reservoirs. Although microseismic data has been used to estimate the SRV, it is high-priced and sometimes overestimated. Additionally, the effect of stress sensitivity on SRV is not considered in abnormal overpressure areas. Thus, the objective of this work is to characterize subsurface fracture networks with stress sensitivity of permeability through the shale gas well production data of the early flowback stage. The flowback regions are first identified with the flowback data of two shale gas wells in South China. Then, we measured the permeability stress sensitivity of the core after fracturing, coupled to the dynamic relative permeability (DRP) calculation to obtain an accurate and simple DRP curve. After that, a comprehensive model is built considering dynamic two-phase relative permeability function and stress sensitivity. Finally, we compared the calculated results with the microseismic data. The results show that the proposed model could reasonably predict the SRV using the flowback data after fracturing. Additionally, compared with the microseismic data, the stress sensitivity should be included, especially in the abnormal overpressure block. It is believed that this mathematical model is accurate and useful. The work provides an efficient approach to estimate stimulated reservoir volume in the shale gas reservoirs.

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