Producing gas from low permeability coals*
Nathan Rayner A , Ross Hendrie B and Michael Bowe CA Arrow Energy Level 19, AM60 Building 42-60 Albert St Brisbane QLD 4000. Email: nrayner@arrowenergy.com.au
B Arrow Energy Level 19, AM60 Building 42-60 Albert St Brisbane QLD 4000. Email: rhendrie@arrowenergy.com.au
C Arrow Energy Level 19, AM60 Building 42-60 Albert St Brisbane QLD 4000. Email: mbowe@arrowenergy.com.au
The APPEA Journal 50(2) 719-719 https://doi.org/10.1071/AJ09083
Published: 2010
Abstract
An assessment framework for selecting optimal drilling and completion, forecasting and operating procedures in low permeability coals.
Themes covered:
low permeability coal;
drilling and production alternatives;
production forecasting and operating procedures; and,
economics and technical feasibility.
Arrow Energy Limited has been exploring for and producing from moderate to low permeability coals for over eight years, both in Australia and internationally. Arrow has developed a systematic approach to assessing the optimal drilling and completion, forecasting and operating procedures to evaluate the best appraisal and development options.
Following the confirmation that the coal resource is of low permeability (less than 5 mD) the selection of the drilling and completion strategies is inter-linked with the expected production and operating procedures. This paper summarises the approach taken by each of these discipline areas and maps out the key alternatives, data requirements and selection criteria used to recommend a production pilot in a low permeability environment.
The first stage of the assessment is to review the drilling alternatives. This includes consideration of horizontal versus deviated or vertical wells, wellbore stability and solids production conditions, stimulation requirements and the production string, including artificial lift.
Production forecasting is conducted with due regard to the technical alternatives screened as part of the drilling assessment. The quality of the forecast will be determined by the available data and the use of the appropriate forecasting tools ranging from analogue assessments, simple single well modelling through to 3D reservoir modelling.
Finally, the production procedures appropriate for the well will be selected based on the well configuration and forecast deliverability as well as regional geology and geomechanics.
This framework ensures that a consistent methodology is applied for selecting well type and operations that maximises the flow potential from our low permeability coals while ensuring due consideration to economics and technical feasibility.
Keywords: low permeability coals, coal seam gas, forecasting, exploration, development, pilot, development, gas content, saturation, permeability, recoverable volume, simulation models, porosity, stress, shrinkage, well design, desorption
Nathan Rayner is an experienced technical manager who, since joining Arrow in October 2008, has held the positions of reservoir manager and petroleum engineering manager before being appointed General Manager Petroleum Engineering in July 2009. In this capacity, Nathan is responsible for the field development planning, production optimisation and reserves assessments of Arrow’s Australian operations. His 12-year petroleum industry career began with engineering and senior engineering appointments at Santos and Origin Energy, where he first began working on coal seam gas projects in 2002. In 2006, Nathan returned to conventional oil and gas with Addax Petroleum and moved to Geneva, Switzerland as the Exploration Evaluation Manager. In this role he was responsible for a large technical team overseeing well site geological operations, reservoir engineering, appraisal planning, prospect portfolio management and business planning. Nathan has both a Bachelor of Engineering (Mining) and Masters of Engineering Science (Petroleum Engineering). |
Ross Hendrie is a senior petroleum engineer with Shell, currently seconded to Arrow Energy as the Production Technology Team Leader. With over 20 years’ experience in the oil and gas field, Ross has specialist expertise in the design, delivery and operation of production wells in both conventional and non-conventional gas developments. He holds a Masters of Engineering (petroleum engineering) from Herriot-Watt University and a Bachelor of Science (applied geology) from the University of Strathclyde. |
Michael Bowe is Arrow Energy’s Exploitation Manager. He is responsible for the planning and implementation of the pilot well program in Arrow’s Australian tenements. His team is responsible for most aspects of the company’s pilot program including hydraulic fracture design and execution, completion, surface installation, commissioning and well operations. Prior to appointment in this position two years ago, Michael was the Production Manager for the Moranbah Gas Project firstly with CH4 in 2006 and subsequently with Arrow Energy. Prior to his work with CH4, Michael spent most of his career in conventional oil and gas with Santos where he was Production Coordinator at Moomba. Michael commenced his career after graduating in geology from Flinders University and started in well site geology positions offshore in the North West Shelf and Bass Strait. |
