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Brisbane, Australia

Connell L.D.,CSIRO | Mazumder S.,Arrow Energy | Sander R.,CSIRO | Camilleri M.,CSIRO | And 2 more authors.
Fuel | Year: 2016

This paper presents the results of a laboratory program of work to measure the coal properties required to apply models for the behaviour of the absolute reservoir permeability during gas production. These measurements were made on core samples from the Bowen Basin of Australia, an important area for coal seam methane production, and involved applying an integrated testing methodology. During the testing the pore pressure was increased in a stepwise fashion with gas adsorption equilibration allowed at each pressure step. The gas content of the intact sample was estimated from the gas taken up during equilibration and the sample swelling in response to adsorption measured. After adsorption had equilibrated, the geomechanical properties were determined through axial loading and measurement of the deformation and the permeability measured with respect to confining pressure. These permeability measurements were then used to estimate the cleat compressibility by fitting the Seidle model to the observations. The results from five coal samples are presented. A method is presented for the calculation of the cleat porosity, a difficult property to determine experimentally as it represents the proportion of the porosity involved in Darcy flow. Thus, the presented method uses a property determined from flow measurements; the cleat compressibility. The measured properties are used in the Shi-Durucan model to predict permeability behaviour with pressure drawdown. The results are compared to the field based estimates from the analysis of Mazumder et al. (2012). © 2015 Elsevier Ltd. Source


Bennett T.,Arrow Energy
Society of Petroleum Engineers - IADC/SPE Asia Pacific Drilling Technology Conference 2012 - Catching the Unconventional Tide: Winning the Future Through Innovation | Year: 2012

From by-product to multi-billion dollar industry, the Coal Seam Gas (CSG) industry in Australia has recently experienced rapid growth however is still facing many challenges. The Australian CSG industry is approaching a cross-road; the transition from a Domestic Gas business to exporting the CSG resources, requiring a significant scale up of current operations. Well design innovation is one of the necessary levers to maximize the full potential of CSG as a competitive energy resource. This paper focuses on the technical challenges associated with driving continuous improvement in drilling and completion practices as a key success factor for competitive performance. The growth expected in the CSG industry over the next few years will be rapid. Arrow Energy plans to increase its production from 150 TJ/day in 2012 to 1350 TJ/day in 2018. This will require increases in drilling performance. Much of the early success will likely be obtained from the transfer of benchmark practices, where relevant, from the more mature global oil and gas industry - rather than from true CSG innovation. However, given the lower cost margins and economics of CSG, this knowledge transfer will need to be coupled with innovative application and new approaches. This paper will discuss the importance of innovation in basis of well design as a lever to drive improvements in CSG in Australia and outline some of the key areas that Arrow Energy is focusing on to achieve this, including: • The need for fit for purpose rigs to meet well design criteria and well safety requirements. • Standardization of well designs and equipment aligned to local government regulations and American Petroleum Institute (API) regulations. • Vendor alignment and incentivized performance to meet company targets. • Problems associated with innovation and difficulties of implementation in short time frames as well as the application of lessons learned from trials. • Well design evolution and optimization of gas recovery. • The importance of adopting a culture of learning and flexibility to implement changes as design standards progress. Copyright 2012, IADC/SPE Asia Pacific Drilling Technology Conference and Exhibition. Source


Johnson R.L.,Jr. | Mazumder S.,Arrow Energy
Society of Petroleum Engineers - International Petroleum Technology Conference 2014, IPTC 2014 - Innovation and Collaboration: Keys to Affordable Energy | Year: 2014

Coalbed methane (CBM) has been considered a relatively mature unconventional gas resource in North America. In Australia, where the CBM or coal seam gas (CSG) industry is nearly two decades old, there have been successful and unsuccessful pilot projects and resources have been slower to develop after nearly twenty-five years since North American technologies were exported internationally. Thus, it is reasonable to believe that there are differences outside North America that have hindered CBM development in Australia. Often CBM pilots owe their degree of success to one of three major factors: geologic or structural setting, reservoir properties, or completion strategies. Most pilot testing have been conducted either to characterize the production from a particular geo-domain associated with certain perceived geological risk and uncertainty or to estimate potential project reserves to a reasonable degree of accuracy. This need to reduce uncertainty is more pronounced in Australia based on the need to balance development decisions, tenure retention requirements, whilst minimising the risk for the upcoming development phase. Often in hindsight, the opportunity to increase the chance of success for good areas or reduce the expenditures in poor areas was achievable through improved reservoir characterisation or better pilot planning. In some cases, the resource volumes are large, but the progression of resources to reserves has been less certainty based on challenges. In this paper we will highlight some key observations from several Australian CSG pilots that led to success or challenges for each case. The authors' goals are to identify key indicators, which if recognised earlier may have increased the rate of success or reduced unnecessary expenditures in these pilot areas. Copyright © 2014, International Petroleum Technology Conference. Source


Kuznetsov D.,Arrow Energy | Giddins M.A.,Schlumberger | Blunt M.J.,Imperial College London
Society of Petroleum Engineers - SPE Asia Pacific Enhanced Oil Recovery Conference, EORC 2015 | Year: 2015

This paper describes a simulation study of the low-salinity effect in sandstone reservoirs. The proposed mechanistic model allows differentiation of water composition effects and includes multi-ionic exchange and double layer expansion. The manifestation of these effects can be observed in coreflood experiments. We define a set of chemical reactions, to describe the contribution of van der Waals forces, ligand exchange, and cation bridging to mobilization of residual oil. The reaction set is simplified by incorporating wettability weighting coefficients that reflect the contribution of different adsorbed ions to the wettability of the rock. Changes in wettability are accounted for by interpolation of the relative permeability and capillary pressure curves between the low and high salinity sets. We also construct and test simplified phenomenological models, one relating the change of the relative permeability to the concentration of a dissolved salinity tracer and another one to the concentration of a single adsorbed tracer. The full mechanistic model, with multiple ion tracking, is in good qualitative agreement with experimental data reported in the literature. A very close agreement with the mechanistic model was obtained for a coreflood simulation using single tracer phenomenological models. The similarity of the results is explained by the fact that the most critical factor influencing the flow behavior was the function used to interpolate between the oil- and water-wet sets of saturation curves. Similar interpolation functions in different models lead to similar oil recovery predictions. This study has developed a detailed chemical reaction model that captures both multicomponent ion exchange and double layer expansion effects, and can be used to improve understanding of low-salinity recovery mechanisms by analyzing their relative contributions. The approach of matching a tracer model to a detailed mechanistic model promises a route to the development of simplified, less computationally demanding proxy models for full field simulation studies. Copyright 2015, Society of Petroleum Engineers. Source


Jin H.,Indiana University | Schimmelmann A.,Indiana University | Mastalerz M.,Indiana University | Pope J.,CRL Energy Ltd. | And 3 more authors.
International Journal of Coal Geology | Year: 2010

Desorption canisters are routinely employed to quantify coalbed gas contents in coals. If purging with inert gas or water flooding is not used, entrapment of air with ~ 78.08 vol.% nitrogen (N2) in canisters during the loading of coal results in contamination by air and subsequent overestimates of N2 in desorbed coalbed gas. Pure coalbed gas does not contain any elemental oxygen (O2), whereas air contamination originally includes ~ 20.95 vol.% O2 and has a N2/O2 volume ratio of ~ 3.73. A correction for atmospheric N2 is often attempted by quantifying O2 in headspace gas and then proportionally subtracting atmospheric N2. However, this study shows that O2 is not a conservative proxy for air contamination in desorption canisters. Time-series of gas chromatographic (GC) compositional data from several desorption experiments using high volatile bituminous coals from the Illinois Basin and a New Zealand subbituminous coal document that atmospheric O2 was rapidly consumed, especially during the first 24 h. After about 2 weeks of desorption, the concentration of O2 declined to near or below GC detection limits. Irreversible loss of O2 in desorption canisters is caused by biological, chemical, and physical mechanisms. The use of O2 as a proxy for air contamination is justified only immediately after loading of desorption canisters, but such rapid measurements preclude meaningful assessment of coalbed gas concentrations. With increasing time and progressive loss of O2, the use of O2 content as a proxy for atmospheric N2 results in overestimates of N2 in desorbed coalbed gas. The indicated errors for nitrogen often range in hundreds of %. Such large analytical errors have a profound influence on market choices for CBM gas. An erroneously calculated N2 content in CBM would not meet specifications for most pipeline-quality gas. © 2009 Elsevier B.V. All rights reserved. Source

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