Development Of Shale Gas Resources Research Articles

Analysis of rigid-flexible coupled torsional vibration and vibration suppression of crankshaft system under multiple working conditions

With the rapid development of shale gas resources in China, there is an increasing demand for large and multiple column compressors. However, this development has brought to light the issue of torsional vibration in compressor crankshaft systems, particularly under variable loads and multiple working conditions. In order to reduce the torsional vibration of the compressor crankshaft and ensure the safe and stable operation of the compressor unit, this study proposes a method for calculating and suppressing torsional vibration in the crankshaft system of a shale gas compressor, which takes into account the flexibility effect of various parts and considers multiple working conditions. The analysis focused on the rigid-flexible coupling torsional vibration characteristics of the crankshaft system under multiple working conditions, considering the flexible deformation of the main bearing, connecting rod, and crankshaft. The study successfully determined the torsional vibration response of the crankshaft system under seven typical working conditions. Furthermore, for the worst conditions, a detailed analysis of the vibration response of the crankshaft system was conducted and carried out a study on suppressing crankshaft torsional vibration through response surface optimization design. The study findings indicate that the compressor system exhibits low-frequency vibrations during operation. The maximum torsional angular deformation at the crank pin of the fourth column is measured to be 0.052°. Following structural optimization, the relative torsional angular deformation of the crank pin is reduced by 25.61% under the worst operating conditions. Moreover, the peak angular velocity of the center of mass is reduced by 22.17%. These results demonstrate a significant suppression effect on torsional vibrations in the compressor crankshaft system, leading to improved working safety.

Treatment technology of shale gas fracturing flowback fluid: a mini review

Shale gas fracturing flowback fluid, characterized by its large volume, complex composition, and potential adverse environmental impacts, has gradually become one of the problems affecting the large-scale development of shale gas resources. Failure to effectively address the treatment of fracturing flowback fluid will severely constrain shale gas development. This paper focuses on the treatment technologies for shale gas fracturing flowback fluid, discussing its water quality characteristics and summarizing the research progress in physical technology, chemical technology, biological technology, and combined technology. Development recommendations are also provided. The results show that shale gas fracturing flowback fluid exhibits characteristics such as complex composition, high viscosity, and high emulsification, and difficult to treat. Individual physical technology, chemical technology, or biological technology is effective in removing certain pollutants from the flowback fluid. Moreover, the combined use of these treatment technologies prove more effective in achieving reuse or discharge standards. With the continuous expansion of shale gas development and increasingly stringent environmental protection requirements worldwide, the volume of flowback fluid requiring treatment is continuously rising. By developing energy-efficient and emission-reduction treatment technologies, and actively recycling and utilizing resources and energy, and adopting clean fracturing fluid system, efficient, energy-saving, environmentally friendly, and economically viable treatment for shale gas fracturing flowback fluid can be achieved.

Environmental Implications of Shale Gas Hydraulic Fracturing: A Comprehensive Review on Water Contamination and Seismic Activity in the United States

Recent scholarship has highlighted the significant environmental impact of the rapidly expanding hydraulic fracturing industry, which is projected to grow from USD 15.31 billion in 2021 to USD 28.93 billion in 2028 at a Compound Annual Growth Rate (CAGR) of 9.5%. Recognizing the need for comprehensive, national-scale evaluations, this review of the literature investigates contamination and induced seismicity associated with shale gas hydraulic fracturing in the United States. Employing systematic reviews of the literature and federal reports up until July 2023, this study reveals multiple areas of concern, including water and soil contamination, seismic activity, and air pollution. A notable finding is the average use of 2.4 million gallons of water per well in hydraulic fracturing, of which only 15–35% is typically retrieved. However, ongoing studies are actively exploring remediation strategies, including advancements in monitoring and treatment technologies, as well as the potential of reusing wastewater for hydraulic fracturing, as exemplified by the Garfield County region in Colorado; they utilized 100% wastewater to mitigate the impact of contamination. These findings underscore the need for stringent regulations, sustained research, and effective management practices. This work emphasizes the importance of a collaborative approach that leverages field studies, experimental investigations, and computational advancements to ensure the responsible development of shale gas resources.

Carboniferous Shale Gas Accumulation Characteristics and Exploration Directions in South China

China has focused on the exploration and development of shale gas resources to reduce its reliance on coal and shift to cleaner energy sources. While significant progress has been made in the Sichuan Basin, unlocking the shale gas potential in other regions of South China has proven challenging due to the complex geology and mountainous terrain. In 2021, Well QSD-1 was deployed in southwestern Guizhou and achieved a daily shale gas flow of 11,011 m3 in the Dawuba Formation, marking the first time an industrial gas flow had been obtained from shale gas drilling in the marine strata of the Upper Paleozoic in China. This breakthrough has deepened the understanding of the southern China Carboniferous marine strata and highlighted key aspects of the formation: (1) Sedimentation occurred in alternating platforms and basins, with most organic-rich shale developed in sloping and basin areas; (2) the formation exhibits favorable static indicators, with a relatively thick section (over 200 m), and an organic carbon content of approximately 1%; (3) the intercalation of argillaceous limestone and shale intervals is conducive to the preservation of shale gas within the formation. These results demonstrate the potential for the Upper Paleozoic in South China to become a significant shale gas producer, which could contribute significantly to China’s energy security. Furthermore, exploring shale gas in the region may have positive economic and environmental impacts, including reducing China’s dependence on coal and decreasing greenhouse gas emissions.

RETRACTED: Impact of nozzle size on shale gas productivity in the Longmaxi formation, Sichuan basin, China

High-pressure differentials are critical in the development of shale gas resources; however, excessive stress can cause damage to propped fractures, resulting in decreased production. The manipulation of nozzle sizes and flow pressure adjustments can indirectly control the effective stress on fractures. In this study, we investigated the impact of flow pressure on fracture permeability and gas production in Longmaxi, Sichuan shale gas wells. By utilizing production data from wells and performing permeability evaluation experiments on Longmaxi shale core samples under varying flow pressures, we developed a novel shale gas well deliverability equation to determine the stress sensitivity of propped fractures. The findings of this study suggest that transitioning the nozzle size from small to large during well production and maintaining the flow pressure between 5 and 7.5 MPa is beneficial. If the nozzle size is reduced from large to small to achieve higher initial gas production, the effective stress on the target field should be maintained at 20 MPa. The methodologies introduced in this research offer innovative approaches for evaluating shale fracture permeability and productivity, providing valuable insights and guidance for the selection of nozzle sizes in the development of shale gas wells.

Shale gas investment decision-making: Green and efficient development under market, technology and environment uncertainties

The investment in shale gas green and efficient development in China faces many uncertain factors that affect the investment decision-making of enterprises, which contributes to China's low-carbon energy transformation and national energy security. Based on the characteristics of China's shale gas resource development and considering the uncertainties in the aspects of market, technology and environment, this paper proposes a real option model to evaluate investment decision-making of China’s shale gas development and uses the Least Square Monte Carlo simulation to solve the investment values and optimal investment timings of shale gas low, moderate, high and ultrahigh productivities under four combination scenarios of financial subsidy and/or carbon emission trading. The results show that the current investment environment in China is not suitable for immediate investment in shale gas development projects. Investors can invest immediately when the initial average daily production reaches at least 30 × 104 m3. And financial subsidy and carbon emission trading help advance the optimal investment timings. According to a sensitivity analysis, appropriate increases in financial subsidy, shale gas price, absolute value of the drift rate of drilling and completion cost and environmental external benefit coefficient are found to improve the investment value and advance the optimal investment timing, while drilling and completion cost and production decline rate have the opposite effect. Therefore, to stimulate the investment, the government and enterprises should adopt some measures such as addressing key problems on technology and equipment, flexibly adjusting subsidy policies and driving forward the carbon emission trading market.

Structural evolution of southern Sichuan Basin (South China) and its control effects on tectonic fracture distribution in Longmaxi shale

We aimed to reveal the structural styles and evolution sequences of the superimposed folding zone in the southern Sichuan Basin, South China, and to predict the distribution rules of tectonic fractures in the Longmaxi shale. The field survey and geological section analysis showed that the structural pattern is characterized by the superposition of near-N–S-trending folds and near-E–W-trending compressive structures. The two structural systems experienced multistage development, and the finalization of the E–W structures was later than the N–S ones. By combining these findings with the back-stripping method and fluid inclusion analysis, the burial, thermal, and structural evolution histories were reconstructed. The results indicate that the E–W-trending compressive structures were finalized at the end of the Late Cretaceous whereas the N–S-trending folds were formed by the Oligocene Epoch. A comparative analysis was conducted to reveal the relationship between tectonic fractures and fold structures. The analysis revealed that the Longmaxi shale in the core zones of the N–S-trending anticlines and the cores and near-core zones of the E–W folds is more likely to show a well-developed natural fracture system, which was verified by fracture observations on shale cores and outcrops. These places have potential for the exploration and development of shale gas resources.

Effects of Fracture Characteristics on Spontaneous Imbibition in a Tight Reservoir

Horizontal well fracturing technology is widely used in the development of shale gas resources. After the fracturing operations, natural and artificial fractures exist in the reservoir at the same time, which has significant effects on spontaneous imbibition to increase shale gas production. Based on nuclear magnetic resonance technology, this work studies the spontaneous imbibition property of fractured shale, including artificial and natural fractures, surface cemented minerals, boundary conditions, etc. The results show that the relaxation time spectra reflect the characteristics of water and gas migration in the rock pore space. The micropores and the small pores are the main storage space for water in shale. After water imbibition starts, the imbibition volume is roughly proportional to the square root of time. Through the comparative experiments on artificial fractures, natural fractures, and seamless cores, it is found that the existence of fractures can significantly promote water imbibition, and the imbibition speed of artificial fractured cores is faster than those of others. Because of the existence of artificial and natural fractures, the number of pores for gas discharge increases, and the imbibed volume is slightly more. When the cemented minerals such as quartzite and calcite are attached to the core surface, they have poor water sensitivity and block some of the pores, thus resulting in a slower imbibition speed. Different boundary conditions will not only affect the contact area between the core and water but also influence the types of imbibition, which changes the water flow path and imbibition speed. This study provides an important insight into spontaneous imbibition in gas shale after the fracturing operations.

A closed-loop integration of scheduling and control for hydraulic fracturing using offset-free model predictive control

As the development of shale gas resources has to be accelerated to satisfy the increasing global natural gas demand, many optimization approaches have been developed to handle the complexity associated with the shale gas system and discern the optimal design and operation strategy. However, it is worth mentioning that the essential hydraulic fracturing operation has not been considered as a dynamic process in the previous studies, which may lead to suboptimal solutions. Motivated by this consideration, we first develop an integrated model to simultaneously consider the scheduling and control of hydraulic fracturing operations to enhance the economic performance of the shale gas system. In particular, a reduced-order model is developed and integrated with the scheduling model to reduce the model complexity. To cope with the plant-model mismatch of the reduced-order model, we propose an online integrated framework with two feedback loops. In the outer loop, the integrated model is solved to determine the scheduling decisions and controller references. Then, an offset-free model predictive control system is designed to track the references online in the inner loop. By utilizing the offset-free model predictive control scheme, the tracking performance is enhanced and the plant-model mismatch is compensated for, which helps avoid dramatic changes in the solutions obtained by re-solving the integrated problem online. The effectiveness of the proposed online integrated framework is demonstrated by considering a hypothetical case study based on Marcellus Shale Play. It shows that the undesirable performance degradation induced by the plant-model mismatch can be decreased by the developed offset-free model predictive control system, and the overall economic performance of the shale gas system is improved with the proposed approach.

Investigation of casing deformation characteristics under cycling loads and the effect on casing strength based on full-scale equipment

Production casing deformation has hindered the safe and economic development of shale gas resources, especially in Weiyuan-Changning Shale Gas field, China. In terms of current literatures, this problem should be attributed to the casing failure induced by varying high loads during the multi-fracturing process. However, the characteristics of casing deformation under cycling loads have hardly been investigated in previous work. In order to realize the casing deformation mechanism during multi-fracturing, the casing deformation real-time monitoring system is improved, based on full-scale casing-cement sheath-formation system (CCFS) combination device. Further, the deformation testing experiments of P110 casing under cycling inner pressure loads, for four conditions (1#-standard condition, 2#-higher inner pressure, 3#-thinner casing, 4#-thicker cement sheath), are carried out … Besides, the reliability of experiment approach is verified, by the consistency of effective circumference strain values in the loading process of first cycle between calculated by elastic theory and determined in this paper. Further, the casing strength under cycling loads is analyzed, to evaluate the casing failure in shale gas well. Results illustrate that the casing under cycling loads are available to generate residual strain, which are reliable to reach 0.035%, 0.104%, 0.042% and 0.027%, respectively, based on above mentioned four testing parameters under 16 cycles. The higher cycling inner pressure significantly increases the residual strain of casing, which is harmful for the casing protection. Increasing the thickness of casing and cement sheath is beneficial to reduce the residual strain of casing. The casing collapsing strength is linearly lowered with cycling number, due to the growing unrecovered strain of casing during multi-fracturing. It precisely explains the phenomenon that casing deformation frequently occurs in the last few fracturing stages of shale gas wells. The casing strength lines from experiment results demonstrate higher accuracy than API (American Petroleum Institute) standard, in evaluating the casing failure of field cases. This work will provide a new criterion for the parameters designs of casing and fracturing in shale gas wells, to reduce the risk of casing deformation during multi-fracturing. • The measurement of casing strain under cycling loads is achieved. • Casing under cycling loads are available to generate residual strain rather than perfect elastic strain. • The equations predicting residual strain of casing are raised by fitting experiment data. • Casing strength lines determined in this paper demonstrate higher accuracy than API standard in shale gas wells.

Pore Size Distribution and Fractal Characteristics of the Nanopore Structure in Organic-Rich Shales Using the Neimark-Kiselev Fractal Approach.

Shale gas has been playing an increasingly important role in meeting global energy demands. The heterogeneity of the pore structure in organic-rich shales greatly affects the adsorption, desorption, diffusion and flow of gas. The pore size distribution (PSD) is a key parameter of the heterogeneity of the shale pore structure. In this study, the Neimark-Kiselev (N-K) fractal approach was applied to investigate the heterogeneity in the PSD of the lower Silurian organic-rich shales in South China using low-pressure N₂ adsorption, total organic carbon (TOC) content, maturity analysis, X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) measurements. The results show that (1) the fractal dimension DN-K obtained by N-K theory better represents the heterogeneity of the PSD in shale at an approximately 1-100 nm scale. The DN-K values range from 2.3801 to 2.9915, with a mean of 2.753. The stronger the PSD heterogeneity is, the higher the DN-K value in shale is. (2) The clay-rich samples display multimodal patterns at pore sizes greater than 20 nm, which strongly effect the PSD heterogeneity. Quartz-rich samples display major peaks at less than or equal to a 10 nm pore size, with a smaller effect on the PSD heterogeneity in most cases. In other brittle mineral-rich samples, there are no obvious major peaks, and a weak heterogeneity of the PSDs is displayed. (3) A greater TOC content, maturity, clay content and pore size can cause stronger heterogeneity of the PSD and higher fractal dimensions in the shale samples. This study helps to understand and compare the PSD and fractal characteristics from different samples and provides important theoretical guidance and a scientific basis for the exploration and development of shale gas resources.

Review of Formation and Gas Characteristics in Shale Gas Reservoirs

An accurate understanding of formation and gas properties is crucial to the efficient development of shale gas resources. As one kind of unconventional energy, shale gas shows significant differences from conventional energy ones in terms of gas accumulation processes, pore structure characteristics, gas storage forms, physical parameters, and reservoir production modes. Traditional experimental techniques could not satisfy the need to capture the microscopic characteristics of pores and throats in shale plays. In this review, the uniqueness of shale gas reservoirs is elaborated from the perspective of: (1) geological and pore structural characteristics, (2) adsorption/desorption laws, and (3) differences in properties between the adsorbed gas and free gas. As to the first aspect, the mineral composition and organic geochemical characteristics of shale samples from the Longmaxi Formation, Sichuan Basin, China were measured and analyzed based on the experimental results. Principles of different methods to test pore size distribution in shale formations are introduced, after which the results of pore size distribution of samples from the Longmaxi shale are given. Based on the geological understanding of shale formations, three different types of shale gas and respective modeling methods are reviewed. Afterwards, the conventional adsorption models, Gibbs excess adsorption behaviors, and supercritical adsorption characteristics, as well as their applicability to engineering problems, are introduced. Finally, six methods of calculating virtual saturated vapor pressure, seven methods of giving adsorbed gas density, and 12 methods of calculating gas viscosity in different pressure and temperature conditions are collected and compared, with the recommended methods given after a comparison.

Optimal design of water pipeline networks for the development of shale gas resources

AbstractOne of the major concerns in shale gas production is water management. Millions of gallons of water are injected to fracture each well and a significant amount returns to the surface as flowback. Operators are increasingly reusing flowback to reduce freshwater consumption and impaired water disposal. Because of this, networks of water pipelines in U.S. shales are growing fast. This work is aimed at addressing the optimal planning of shale gas operations in multiple wellpads together with the design of water distribution networks (WDN). We propose a multiperiod mixed‐integer linear programming model to solve the challenging stay‐or‐mobilize trade‐off. The proposed model permits to schedule operations at a detailed level, accounting for the WDN required to maximize the reuse of impaired water. We present illustrative examples involving up to 20 pads, 4 frac‐crews, and 100 wells developed over 1 year, showing that the design of the WDN can be effectively optimized.

Fracture Modeling and Productivity Prediction Technology of Shale Reservoir Based on Multivariate Data

The practice of fracture network fracturing in shale gas layers indicates that the formation of complex fracture networks is directly related to the probability of obtaining a sufficiently large reservoir to effectively rebuild the volume and the ability to obtain high economic benefits. With the continuous deepening of shale gas exploration and development, it is found that the current artificial fractures have slopes, branches and asymmetric distribution. As a result, the production difference between different horizontal wells in the same platform and different fracturing sections of the same horizontal well is obvious. How to optimize the exploration and development plan and promote the economical and effective development of shale gas resources is the most important problem currently facing. The post-evaluation technology of reservoir reconstruction effect has become a key technology. Therefore, it is of great production significance to carry out post-evaluation work by integrating multivariate data. This article takes the SiChuan WeiYuan Shale Gas Demonstration Area as an example, and uses microseismic results and surface seismic data, geology, logging, fracturing and production dynamics data to carry out fracturing fracture modeling and productivity prediction. Provided guidance for fracturing design optimization, development well location, well spacing deployment, and development effectiveness, with good application results.

A New Model between Dynamic and Static Elastic Parameters of Shale Based on Experimental Studies

During the exploration and development of shale gas resources, elastic parameters provide crucial geomechanical information for shale gas extraction and hydraulic fracturing projects. Static elastic parameters are usually adopted in rock mechanics analyses and hydraulic fracturing designs and are generally obtained from experimental tests using core samples collected from the subsurface. However, experimental core data could be discontinuous despite the high costs. Dynamic methods, including well logging and seismic survey, are applied in practice. Given the difference between static and dynamic elastic parameters, dynamic elastic parameters gained from those aforementioned dynamic methods need to be converted to static elastic parameters. Currently, static and dynamic elastic parameter test data are often directly used in converting dynamic elastic parameters to static elastic parameters without consideration of the influence of rock mineral composition on the difference between elastic and dynamic elastic properties. Consequently, the conversion results cannot fully reflect reservoir geomechanical conditions. In this research, the rock mineral composition is analyzed, and the effects of various mineral components on static and dynamic elastic parameters of shale are discussed. A new conversion model is established by taking into account the rock mineral composition. The new model is capable of providing improved conversion results and thus can be applied in shale gas extraction and hydraulic fracturing projects at the target reservoir. Therefore, this research has both theoretical and practical impacts.

Data driven techno-economic framework for the development of shale gas resources

This work presents a data driven techno-economic framework that combines upstream, midstream and downstream operations to optimize profitability of shale projects. This framework is illustrated using a shale gas supply chain structure planned for development and integration in an over-supplied gas market. Field development strategies are developed based on applying machine learning techniques to an existing field. Alternative development strategies are implemented on the integrated production-modeling platform RESOLVE–REVEAL to simulate hydrocarbon/water production. Long-short term memory (LSTM) neural networks are developed to predict gas demand and freshwater availability. Long-term strategic planning is achieved using a mixed-integer non-linear programming (MINLP) formulation. Results indicate a net present value (NPV) of 205.56 MMUS$ for optimal infrastructure design, gas and liquids transportation and distribution, and water management after 54-well integration. Additionlly, results provide an optimal gas storage schedule that supports shale asset profitability. Application of this techno-economic approach improves profitability projections for shale enterprises.

Improved Method for Measuring the Permeability of Nanoporous Material and its Application to Shale Matrix with Ultra-Low Permeability.

Nanoporous materials have a wide range of applications in clean energy and environmental research. The permeability of nanoporous materials is low, which affects the fluid transport behavior inside the nanopores and thus also affects the performance of technologies based on such materials. For example, during the development of shale gas resources, the permeability of the shale matrix is normally lower than 10−3 mD and has an important influence on rock parameters. It is challenging to measure small pressure changes accurately under high pressure. Although the pressure decay method provides an effective means for the measurement of low permeability, most apparatuses and experiments have difficulty measuring permeability in high pressure conditions over 1.38 MPa. Here, we propose an improved experimental method for the measurement of low permeability. To overcome the challenge of measuring small changes in pressure at high pressure, a pressure difference sensor is used. By improving the constant temperature accuracy and reducing the helium leakage rate, we measure shale matrix permeabilities ranging from 0.05 to 2 nD at pore pressures of up to 8 MPa, with good repeatability and sample mass irrelevance. The results show that porosity, pore pressure, and moisture conditions influence the matrix permeability. The permeability of moist shale is lower than that of dry shale, since water blocks some of the nanopores.

PUBLIC-PRIVATE PARTNERSHIP IN THE DEVELOPMENT OF SHALE GAS RESOURCES IN UKRAINE

The article considers the possibilities of using the institution of public-private partnership in the development of natural gas resources from shale formations. The economic expediency of using public-private partnership in the development of these resources is due to the need to overcome deficiencies in the existing system of nature management and the use of an effective institute of civil ownership of natural resources. Features of public-private partnership in the development of natural resources, the possibility of applying various types of transactions, methodical approaches to the formation of information necessary for their conclusion, relating to the content of gas in slate formations, forecasting the productivity of wells, the marginal cost limits, at which a profitable extraction of shale gas is possible , capitalization of shale gas resources. The criteria for the selection of the most promising zones of "sweeps spots" (sweet places) are established on significant areas of their distribution, which is the main task of exploration for the purpose of exploration, exploration and extraction of shale gas. It was investigated that the institutions of financing shale gas extraction are important in concluding public-private partnership agreements, the key role of which is the capitalization of natural resources - the process of conversion of factors of production into capital. The method of capitalization of shale gas resources in the subsoil is described, which will enable application of the concept of project investment.
 The directions of perfection of the institute of public-private partnership during development of shale gas resources are determined.
 Key words: public-private partnership, shale gas, characteristics of shale formations, gas content, wells productivity, the cost of unprofitable shale gas extraction, investment efficiency, capitalization of shale gas resources.

A slip-flow model for multi-component shale gas transport in organic nanopores

With the rapid development of shale gas resources, the accurate simulation of shale gas development process is becoming more and more important. Shale gas transport through nanopores of shale formation is the basic of shale gas development simulation. At present, the effect of impurities on methane transport through nanopores is neglected. In this paper, a novel model is presented for simulating multi-component shale gas transport through nanopores of shale formation. The effects of multi-component, slippage flow, and Knudsen diffusion are considered in the model. Results show that when the shale gas in nanopores is very thin, the Knudsen diffusion plays the dominant role over wide range of nanopore radius. While the effect of multi-component on Knudsen number and contribution degree can be neglected, both of the slippage flow rate and the Knudsen diffusion rate increase with increasing of CO2 content. Under medium pressure condition, there exists two turning points where the slippage flow and Knudsen diffusion take turns in charge of the shale gas transmission. Under high pressure condition, the slippage flow is the dominant factor over wide range of nanopore sizes. While the conductivities increase with decreasing methane content, the effect of multi-component on contribution degrees of slippage and Knudsen diffusion can be neglected.

Influence of Heterogeneous Reservoirs with Different Depths on Casing Deformation in Fuling Area

In shale gas horizontal well fracturing operations, casing deformation and cement ring damage occur mostly in heterogeneous formations. Based on the characteristics of shale gas reservoirs in China and related literatures, this paper establishes a finite element model of heterogeneous stratum for the Fuling shale gas field and studies the effects of heterogeneity on casing deformation at different depths. In the heterogeneous stratigraphic model, the effects of shallow reservoir heterogeneity and deep reservoir heterogeneity on casing deformation were analyzed. The results show that the shallow reservoir heterogeneity and deep reservoir heterogeneity affect the casing deformation in different aspects; the stress that is subjected to casing in the shallow reservoir is greater than casing in the deep reservoir; at the lithological interface, the abrupt of stress change in the deep reservoir is significantly larger than that in the shallow reservoir. This conclusion is also applicable to other shale gas fields in China; In the development of shale gas resources, the shallow reservoirs should focus on the overall strength design of casings, the deep reservoirs should focus on the strength design of casings at lithological interface points.