Shale Play Research Articles

High-Fidelity Microseismic-Data Acquisition in the Midland Basin Wolfcamp Shale Play

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 178715, “High-Fidelity Microseismic-Data Acquisition in the Midland Basin Wolfcamp Shale Play,” by Robert Hull, Robert Meek, Brian Wright, Hallie Meighan, Jake Lempges, and Austin von der Hoya, Pioneer Natural Resources, prepared for the 2015 Unconventional Resources Technology Conference, San Antonio, Texas, USA, 20–22 July. The paper has not been peer reviewed. In the Permian Wolfcamp shale formation in west Texas, density fields of microseismic events were mapped in four dimensions and variations were noted in the geometry of the hydraulic stimulation as well as in the development of pressure away from the perforations. In addition to aiding wellspacing decisions, these data were used to study individual-well geometries and compare variations in the microseismic response between adjacent wells. Results The data sets demonstrate that high-fidelity microseismic data can be acquired by use of downhole tractored and multiobservational well-imaging techniques to understand stimulations and the stress fields better as indicated by microseismic data. The data are called high-fidelity because, in general, they are excellent data that are consistent and conform to standard understandings of stimulations. Beyond the robustness in event counts, the data typically have a high signal/noise ratio with high-quality waveforms for picking and consistent hodograms across the tools within the array. Additionally, the P- and S-wave picks are orthogonal to each other and often include the P amplitude and the horizontal (Sh) and vertical (Sv) S amplitudes. The data demonstrate Clearly defined nodal planes indicating good P- and S-wave amplitude stability indicative of uniform radiation patterns directly related to the hydraulic mechanics and fracture networks Variations in observed complexity of event clouds related to formations Variations in event characteristics related to stress shadows from adjacent prior stimulations Expanding on the first observation, for a number of the data sets with an offset stimulation, P- and S-wave amplitude ratios vary azimuthally with respect to the observation well. Fairly uniform radiation patterns appear to be caused by consistent failure mechanisms. These composite P/Sh amplitude displays provide low-cost source mechanism information and highlight a common nodal plane as imaged back to the observation well. The amplitude ratios suggest a uniform mechanism that occurs during hydraulic stimulation that may be related to in-situ conditions of altered rock within the formation or the hydraulic stimulation itself. It is difficult to determine if the natural fractures are aligned in a certain orientation or the propagation of stress and slippage is related to the developing fracture. The microseismic data suggest a dominance of strike/slip failures because the log of Sh/P changes with a 90° rotation. If the data had plotted more as with a 180° rotation, two possibilities would exist for interpretation, including a vertical dip/slip mechanism or a horizontal bedding-plane slip. In the latter, the fracture opening is accommodated by shearing along the bedding planes as the fracture opens vertically.

Adequacy of Current State Setbacks for Directional High-Volume Hydraulic Fracturing in the Marcellus, Barnett, and Niobrara Shale Plays

Background:There is an increasing awareness of the multiple potential pathways leading to human health risks from hydraulic fracturing. Setback distances are a legislative method to mitigate potential risks.Objectives:We attempted to determine whether legal setback distances between well-pad sites and the public are adequate in three shale plays.Methods:We reviewed geography, current statutes and regulations, evacuations, thermal modeling, air pollution studies, and vapor cloud modeling within the Marcellus, Barnett, and Niobrara Shale Plays.Discussion:The evidence suggests that presently utilized setbacks may leave the public vulnerable to explosions, radiant heat, toxic gas clouds, and air pollution from hydraulic fracturing activities.Conclusions:Our results suggest that setbacks may not be sufficient to reduce potential threats to human health in areas where hydraulic fracturing occurs. It is more likely that a combination of reasonable setbacks with controls for other sources of pollution associated with the process will be required.Citation:Haley M, McCawley M, Epstein AC, Arrington B, Bjerke EF. 2016. Adequacy of current state setbacks for directional high-volume hydraulic fracturing in the Marcellus, Barnett, and Niobrara Shale Plays. Environ Health Perspect 124:1323–1333; http://dx.doi.org/10.1289/ehp.1510547

Earthquakes in Northwest Louisiana and the Texas–Louisiana Border Possibly Induced by Energy Resource Activities within the Haynesville Shale Play

ABSTRACT We utilize Transportable Array data to survey regional seismicity in east Texas and northwest Louisiana. Through analyst review and a waveform‐matching technique, we identify 58 earthquakes occurring between April 2010 and July 2012. The earthquakes spatially cluster within two main zones, near Timpson, Texas, and within Bienville Parish, Louisiana; minor clusters occur in the Texas–Louisiana border region. Although the Timpson earthquakes have been studied previously, we identify many undetected earthquakes that occurred in 2010, about two years prior to the 17 May 2012 M w 4.8 earthquake, which has been linked to wastewater injection. The Bienville Parish sequence, which consists of magnitude 0.5–1.9 earthquakes in mid‐ to late‐2011, occurred about 10 km from wells that began injecting at relatively modest rates (∼40,000 barrels (bbl) per month) in late 2010 but within a few kilometers of production wells that were being hydraulically fractured around the same time period. An additional cluster of seismicity was observed, near Center, Texas, with some seismicity occurring in the months prior to the start of wastewater injection and the largest earthquake in that sequence occurring when injection exceeded 200,000 bbl/month; this may be a case in which injection into a seismically active area promoted a larger earthquake. Finally, there was also seismicity observed near the Toledo Bend Reservoir in Louisiana. The evidence concerning some of the sequences indicates they might be associated with either hydraulic fracturing or recent increases in wastewater injection at wells within the unconventional Haynesville shale gas play. The results of this study highlight the need for more extensive seismic monitoring in the central and eastern regions of the United States of America.

Machine Learning as a Reliable Technology for Evaluating Time/Rate Performance of Unconventional Wells

Summary Production-data analysis is a practice fraught with inconsistencies. In the application of any single model, the quantity of answers arrived at by experienced evaluators is often equal to the number of evaluators analyzing the data. The cause of such inconsistency is bias on the part of evaluators. Although the colloquial use of bias typically implies systematic error, in this paper, we define bias as an expression of belief by the evaluator. With the lack of recognition of bias, no means exists with which to gauge its accuracy. A method that requires explicit expression of one's bias in time/rate decline behavior can provide an objective means with which to evaluate it. In this work, we present a machine-learning method to forecast production in unconventional, liquid-rich shale and gas-shale wells. Methods were developed for probabilistic decline-curve analysis with Markov-chain Monte Carlo simulation (MCMC) as a means to quantify reserves uncertainty, to incorporate prior information (i.e., bias), and to do so quickly. We extend the existing approaches by (a) a modified likelihood-distribution function to improve “learning” of production data, (b) integration of the transient hyperbolic model (THM) to explicitly define the various flow regimes present in unconventional wells, (c) a method for construction of discretized “percentile neighborhood” forecasts, and (d) construction of type wells from an analyzed well population. The accuracy and calibration of the method are demonstrated by an analysis of 136 wells in the Elm Coulee Field of the Bakken. Quantification of change in time/rate behavior caused by completion design, and the inference of physical behavior and properties, is demonstrated with a tight oil play in the Cleveland sand formation of the Anadarko Basin, as well as a shale play in the Wolfcamp formation of the Permian Basin. We show that this implementation of supervised machine learning, in combination with well-calibrated bias, improves the estimation of uncertainty of the posterior distribution of forecasts. In addition, hindcasts performed at various time intervals result in accurate estimation of mean five-year cumulative production. We observe that the “percentile neighborhood” forecasts are reasonable fits of production data comparable to those that may be created by a human evaluator, and that the type well computed is representative of the decline behavior of the well population upon which it is based. We conclude that, given the speed and accuracy of the process, machine learning is a reliable technology as defined by the US Securities and Exchange Commission (SEC), and can significantly improve the process of production forecasting by human evaluators for most unconventional wells with consistent trends of production history.

Universal Kriging of functional data: Trace-variography vs cross-variography? Application to gas forecasting in unconventional shales

In this paper we investigate the practical and methodological use of Universal Kriging of functional data to predict unconventional shale gas production in undrilled locations from known production data. In Universal Kriging of functional data, two approaches are considered: (1) estimation by means of Cokriging of functional components (Universal Cokriging, UCok), requiring cross-variography and (2) estimation by means of trace-variography (Universal Trace-Kriging, UTrK), which avoids cross-variogram modeling. While theoretically, under known variogram structures, such approaches may be quite equivalent, their practical application implies different estimation procedures and modeling efforts. We investigate these differences from the methodological viewpoint and by means of a real field application in the Barnett shale play. An extensive Monte Carlo study inspired from such real field application is employed to support our conclusions.

Application of high-resolution 2D–3C seismic for characterization of the perspective Jurassic shale play in Central Poland

Here we show the application of broadband (4–120Hz) 2D–3C seismic for characterization of the perspective Jurassic shale play in Central Poland. Data were acquired along a network of 250km 2D profiles using single-point, densely spaced receivers (digital 3C sensors) and acquisition was focused on providing both high-resolution and broadband seismic that would enable structural imaging and quantitative interpretation of the key stratigraphic horizons in the Mesozoic sedimentary cover. Such acquisition parameters resulted in good quality data and allowed for more flexibility during processing, e.g., unaliased F–K filtering or digital group forming for ground-roll removal. Processing was oriented to preserve relative amplitudes and the broadband character of the dataset as the input for future quantitative interpretation. We obtained a high-resolution stratigraphic image of the target Upper Jurassic (Upper Kimmeridgian–Tithonian) sequence as well as overall structural portrait of this part of Mid-Polish Trough characterized by strong imprint of the salt tectonics. Lateral continuity of particular stratigraphic sequences has been determined and a more precise structural context for deposition and present-day structure of the Upper Kimmeridgian–Tithonian has been established.

Revised models for determining TOC in shale play: Example from Devonian Duvernay Shale, Western Canada Sedimentary Basin

Determination of total organic carbon (TOC) is essential in unconventional shale resource play evaluation. Indirect method, such as petrophysical approach, can provide a fast, convenient and cost efffective means for TOC estimation from well logs. Among the publically available approaches, the ΔlogR method is a popular one in conventional source rock evaluation and has been applied to unconventional resource play evaluation by many practitioners. Careful examination of the method finds that improvements can be made for a better TOC estimation with relaxed limitations. This study proposes the following revisions on the original ΔlogR method: 1) allowing estimation of petrophysical parameters from the targeted source rock rather an assumed linear approximation, 2) using additional logs to improve TOC prediction, and 3) replacing LOM (level of organic metamorphism unit) with a more commonly used thermal indicator Tmax for convenience. Depending on data or preference, the choice of using different porosity logs (density versus sonic) and parameter estimation methods (cross-plot method versus data-driven approaches) makes the revised method flexible for application. We present the revisions along with application examples from the Devonian Duvernay Shale in the Western Canada Sedimentary Basin to demonstrate the application of the improved ΔlogR method in shale gas evaluation. Comparison of the results from the revised method and the original one reveals that the revised models provide better and unbiased estimates of TOC with a higher correlation coefficient and bell-shaped residues centered at zero.

Water Management: Lessons Learned and Considerations for a Shale Play in Argentina

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 174118, “Water Management: What We Have Learned and What We Need To Consider for Developing a Shale Play in Argentina,” by J.C. Bonapace, SPE, Halliburton, and F.G. Alric, A. Angeloni, and L. Zangari, Total E&P, prepared for the 2015 SPE Latin American and Caribbean Health, Safety, Environment, and Sustainability Conference, BogotÁ, Colombia, 7–8 July. The paper has not been peer reviewed. Recently, exploration and development of shale plays in Argentina, such as the Vaca Muerta, have begun. To achieve commercial production, this type of reservoir must be stimulated by hydraulic fracturing using large volumes of water. This paper discusses aspects of water logistics necessary during the well-completion phase, fracture-treatment designs applied in Vaca Muerta, and laboratory studies performed on flowback and produced water to help evaluate the potential for water reuse. Introduction Well stimulation using hydraulic fracturing has been used widely for producing oil and gas reservoirs in Argentina since the 1960s. This stimulation technique has been applied in the five hydrocarbon-producing basins shown in Fig. 1, as well as in a variety of formations and types of reservoirs, such as conventional, tight, and, more recently, shale. The majority of shale exploration and development has been in the Vaca Muerta formation, but work has also been assessed in other formations, such as Los Molles, Cacheuta, D-129, and Agrio. Experience gained related to water management in these shale plays during the completion of more than 40 wells (more than 200 hydraulic fractures) by different operators is presented in the paper. Furthermore, laboratory studies were conducted on treated and untreated flowback water, and assessment of its use as fracturing-fluid water is presented. Water Sources and Stimulation Given the economic potential of the Vaca Muerta play, the focus lies on this reservoir. The primary sources of water in the Neuquén basin used to develop these hydrocarbon resources are rivers (Neuquén, Limay, and Colorado), lakes, reservoirs (Cerro Colorado and Pellegrini), or groundwater sources, such as wells with low salinity. These types of wells for water supply need a permit from the regulatory authority, and produced water is not suitable for human consumption or farming.

Effective Technology Strategy for Shale Plays

This paper presents the results of an analysis of the current state of shale play development in the United States to determine the recent advances in the understanding of reservoir behaviors and the most effective uses of new techniques and technologies. It emphasizes reservoir optimization, and the application of new technologies and techniques to reduce costs and to improve recoverability of hydrocarbons to improve ultimate recoverable reserves. It specifically addresses issues of decline curves, stranded pay between laterals, stacked pay logistics, and pad drilling. In addition, the presentation looks at sweet spot optimization, effective investments, hydraulic fracturing, and geomechanics. In a low price environment, with extreme volatility, the paper also examines strategies employed by companies to preserve their assets and recoverable reserves, which include drilling but not completing and alternative stimulation strategies.

Optimal Design of Thermal Membrane Distillation Systems for the Treatment of Shale Gas Flowback Water

Shale gas production is associated with the significant consumption of fresh water and discharge of wastewater. The flowback wastewater is tied to the hydraulic fracturing technology used for completing and stimulating the horizontal wells in the very tight formations characterizing the shale formation. Treatment and reuse of these large volumes of wastewater can lead to substantial savings in fresh water usage and reduction of the negative environmental impact thereby enhancing sustainability of the shale gas industry. Such treatment requires selective and cost-effective technology.Thermal membrane distillation (TMD) is an emerging technology that offers several advatanges such as high selectivity in separating water from inorganic solutes and modular nature that can accommodate a wide range of flows. It can also utilize low-level heats that are typically available from shale-gas production and processing.The objective of this work is to develop an optimization approach for the design of TMD systems to treat flowback water. A multi-period formulation is developed to account for the time-based variation in the flowrate and concentration of the flowback water. Modeling equations are used to relate design and operating variables to performance and cost. The optimization formulation also accounts for the period-based changes in the required design and operating variables and reconciles them over the selected periods. Other constraints include quality of the permeate and water-recovery ratio. The optimization formulation and design approach are applied to a case study for the treatment of flowback water for the Marcellus Shale Play. For 75% water recovery, the cost of the permeate is about $2.6/m3. As higher recoveries are sought, the cost per m3 of permeate increases due to capital productivity factors in dealing with the decreasing amount of flowback water over time. The results are reported using a Pareto chart that trades off recovery objectives with cost of treated water.

Competitive Sorption of Methane/Ethane Mixtures on Shale: Measurements and Modeling

As the primary mechanism of gas storage in shale, sorption phenomena of CH4 and other hydrocarbons in the micropores and mesopores are critical to estimates of gas-in-place and of the long-term productivity from a given shale play. Since C2H6 is another important component of shale gas, besides CH4, knowledge of CH4–C2H6 binary mixture sorption on shale is of fundamental significance and plays a central role in understanding the physical mechanisms that control fluid storage, transport, and subsequent shale-gas production. In this work, measurements of pure component sorption isotherms for CH4 and C2H6 for pressures up to 114 and 35 bar, respectively, have been performed using a thermogravimetric method in the temperature range (40–60 °C), typical of storage formation conditions. Sorption experiments of binary (CH4–C2H6) gas mixtures containing up to 10% (mole fraction) of C2H6, typical of shale-gas compositions, for pressures up to 125 bar under the aforementioned temperature conditions have also been co...

Optimal dynamic allocation of mobile plants to monetize associated or stranded natural gas, part I: Bakken shale play case study

Associated or stranded natural gas presents a challenge to monetize due to its low volume and lack of supporting infrastructure. Recent proposals for deploying mobile, modular plants, such as those which perform GTL (gas-to-liquids) conversion or produce LNG (liquefied natural gas) on a small scale, have been identified as possible attractive routes to gas monetization. However, such technologies are yet unproven in the marketplace. To assess their potential, we propose a multi-period optimization framework which determines the optimal dynamic allocation and operating decisions for a decision maker who utilizes mobile plants to monetize associated or stranded gas. We then apply this framework to a case study of the Bakken shale play. Our framework is implemented to determine the optimal NPV (net present value) which would be realized over a twenty-year time frame. Sensitivity studies on the technology costs and conversion inputs conclude that the profitability and viability of mobile technologies remain valid for a wide range of possible inputs.

Quantitative pore characterization and the relationship between pore distributions and organic matter in shale based on Nano-CT image analysis: A case study for a lacustrine shale reservoir in the Triassic Chang 7 member, Ordos Basin, China

The microstructure of shale has always been of interest in studies associated with shale gas reservoirs. In addition, the influence of the presence of organic matter on the pore distribution is not well-understood. Although considerable attention has been given to the total organic carbon (TOC) content together with the total porosity, concerns regarding investigating the pores in rocks separately according to the different media where the pores are distributed are still rare. This paper presents a comparative study of the pore size distribution (PSD) in organic matter (OM) and the mineral matrix (MM) within the same sample with the OM-hosted pores and MM-hosted pores accurately distinguished and quantitatively analysed. Four shale samples from a shale play in the Ordos Basin are scanned using nano-CT scanning with a resolution of 65 nm. The calculated total organic carbon (TOC) of the samples are 3.48%, 4.47%, 2.76%, and 3.01% with corresponding porosities of 4.30%, 4.97%, 4.50%, and 4.74%, respectively. The results show that more of the large pores exist in the OM with better connectivity and irregular shapes, while the pores in the MM are smaller on average, have less connectivity, and primarily consist of tiny spheres. The pore-medium-ratio (PMR) was introduced to illustrate the pore volume distribution characteristics within each specific medium. The PMR is a ratio between the volume of pores in a specific medium (i.e., MM or OM in this study) and the volume of that medium. According to the PMR curves, the small pores are distributed homogeneously, while the large pores have a heterogeneous distribution and are medium-dependent. It is concluded that the OM affects the pore distribution in three aspects: 1. the OM has a higher PMR; 2. most large pores occur in the OM; and 3. the small pores in the MM tend to appear around the OM. Insights into the various distributions of the pores have been developed. Pores in either medium exhibit an exponential distribution in number. Three sections of the pore volume distribution and surface area distribution are found. Furthermore, the concept is verified that small pores have a large effect on the surface area, while large pores have a large effect on the pore volume.

Deciphering and handling uncertainty in shale gas supply chain design and optimization: Novel modeling framework and computationally efficient solution algorithm

The optimal design and operations of shale gas supply chains under uncertainty of estimated ultimate recovery (EUR) is addressed. A two‐stage stochastic mixed‐integer linear fractional programming (SMILFP) model is developed to optimize the levelized cost of energy generated from shale gas. In this model, both design and planning decisions are considered with respect to shale well drilling, shale gas production, processing, multiple end‐uses, and transportation. To reduce the model size and number of scenarios, we apply a sample average approximation method to generate scenarios based on the real‐world EUR data. In addition, a novel solution algorithm integrating the parametric approach and the L‐shaped method is proposed for solving the resulting SMILFP problem within a reasonable computational time. The proposed model and algorithm are illustrated through a case study based on the Marcellus shale play, and a deterministic model is considered for comparison. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3739–3755, 2015

Unlocking Key Factors of Shale Play Sweet Spotting Appraisal - Field Case Studies From China and North America

Unlocking Key Factors of Shale Play Sweet Spotting Appraisal - Field Case Studies From China and North America

Spatial and temporal trends in freshwater appropriation for natural gas development in Pennsylvania's Marcellus Shale Play

AbstractWe characterize the appropriation of surface water for the extraction of natural gas from Pennsylvania's Marcellus Shale, and we examine the influences of these diversions on stream flows at 300 sites. Our analysis reveals that permitted withdrawals range from 50 m3/d to more than 18,000 m3/d and that water is taken from streams of all sizes, from headwater streams to eighth‐order rivers. Flow alteration varies inversely with watershed area and, for larger streams, is compounded by upstream withdrawals. The ratio of daily permitted withdrawal to median stream flow ranges from 0.0001 to unity, although low flows in most, but not all, smaller streams are protected by pass‐by flow requirements. Temporal changes in surface water withdrawals track gas well completion activity, rather than changes in operational strategies, and while reuse of wastewater has increased since 2009, freshwater accounted for 75% of water used in hydraulic fracturing through the peak in gas well completion activity.

Mechanisms of boron removal from hydraulic fracturing wastewater by aluminum electrocoagulation

HypothesesBoron uptake from highly saline hydraulic fracturing wastewater by freshly precipitated amorphous Al(OH)3 precipitates is due to ligand exchange and complexation with surface hydroxyl groups. Consequently, aluminum electrocoagulation can be a feasible approach to remove boron from flowback/produced water. ExperimentsActual hydraulic fracturing wastewater containing ∼120mg/L boron from the Eagle Ford shale play was employed. Electrocoagulation was performed over a range of aluminum dosages (0–1350mg/L), pH 6.4 and 8, and high current densities (20–80mA/cm2) using a cylindrical aluminum anode encompassed by a porous cylindrical 316-stainless steel cathode. Direct measurements of boron uptake along with its chemical state and coordination were made using Attenuated Total Reflection-Fourier Transform Infrared spectroscopy (ATR-FTIR) and X-Ray Photoelectron Spectroscopy. FindingsBoron removal increased monotonically with aluminum dosage and was higher at pH 8, but remained relatively constant at ⩾20mA/cm2. Chloride ions induced anodic pitting and super-Faradaic (131% efficiency) aluminum dissolution and their electrooxidation produced free chlorine. ATR-FTIR suggested outer-sphere and inner-sphere complexation of trigonal B(OH)3 with Al(OH)3, which was confirmed by the BO bond shifting toward lower binding energies in XPS. Severe AlO interferences precluded evidence for tetrahedral B(OH)4− complexation. No evidence for co-precipitation was obtained.

Shale Gas Supply Chain Design and Operations toward Better Economic and Life Cycle Environmental Performance: MINLP Model and Global Optimization Algorithm

In this work, the life cycle economic and environmental optimization of shale gas supply chain network design and operations is addressed. The proposed model covers the well-to-wire life cycle of electricity generated from shale gas, consisting of a number of stages including freshwater acquisition, shale well drilling, hydraulic fracturing and completion, shale gas production, wastewater management, shale gas processing, electricity generation as well as transportation and storage. A functional-unit based life cycle optimization problem for a cooperative shale gas supply chain is formulated as a multiobjective nonconvex mixed-integer nonlinear programming (MINLP) problem. The resulting Pareto-optimal frontier reveals the trade-off between the economic and environmental objectives. A case study based on Marcellus shale play shows that the greenhouse gas emission of electricity generated from shale gas ranges from 433 to 499 kg CO2e/MWh, and the levelized cost of electricity ranges from $69 to $91/MWh. A g...

A Comparison of Three Nonoxidizing Biocides and Chlorine Dioxide in Treating Marcellus Shale Production Waters

Summary Chlorine dioxide (ClO2), a relative new addition to the oil and gas fracturing industry (especially for production-water treatment for reuse), has superior microbial efficacy compared with currently used nonoxidizing biocides at their lowest and mid-range US Environmental Protection Agency approved concentrations. ClO2 is the only antimicrobial treatment to exhibit complete kill of any of the bacterial populations [except tetrakishydroxymethyl phosphonium sulfate (THPS) at 208 ppm (commodity basis) in 100% Marcellus shale production water], and demonstrated greater than 5.16 log10 reduction even at the lowest ClO2 residual tested (i.e., 1.19 ppm residual; 9 ppm dose). As a result, ClO2 should be considered a potentially viable option when selecting a biocide for treating fracturing production waters for reuse in the Marcellus shale play.

Scenarios for shale gas development and their related land use impacts in the Baltic Basin, Northern Poland

Scenarios for potential shale gas development were modelled for the Baltic Basin in Northern Poland for the period 2015–2030 using the land allocation model EUCS100. The main aims were to assess the associated land use requirements, conflicts with existing land use, and the influence of legislation on the environmental impact. The factors involved in estimating the suitability for placement of shale gas well pads were analysed, as well as the potential land and water requirements to define 2 technology-based scenarios, representing the highest and lowest potential environmental impact. 2 different legislative frameworks (current and restrictive) were also assessed, to give 4 combined scenarios altogether. Land consumption and allocation patterns of well pads varied substantially according to the modelled scenario. Potential landscape fragmentation and conflicts with other land users depended mainly on development rate, well pad density, existing land-use patterns, and geology. Highly complex landscapes presented numerous barriers to drilling activities, restricting the potential development patterns. The land used for shale gas development could represent a significant percentage of overall land take within the shale play. The adoption of appropriate legislation, especially the protection of natural areas and water resources, is therefore essential to minimise the related environmental impact.