The production profile is the defining feature and the source of most commercial disappointment. A CBM well produces water at high rate and little or no gas initially, and gas rate builds as reservoir pressure falls below desorption pressure across an expanding region. Peak gas rate may occur one to three years after first production. This means early production data does not indicate ultimate performance, wells that look poor may improve, and the capital is spent long before the revenue arrives. Development economics are correspondingly sensitive to the length of the dewatering period.

Permeability behaves in two opposing ways as the reservoir depletes. Rising effective stress compresses the cleats and reduces permeability, as in any reservoir. But desorption removes gas from the coal matrix, which causes the matrix to shrink, which widens the cleats and increases permeability. Which effect dominates varies between coals and changes through depletion, and the net permeability trajectory strongly influences long term well performance. Coals in which shrinkage dominates can show permeability increasing several fold over field life.

Gas content measurement is the foundation of resource estimation and carries substantial uncertainty. Desorption canister testing measures lost gas during core recovery, desorbed gas over a period of days or weeks and residual gas after crushing, and the lost gas estimate in particular is an extrapolation. Isotherm measurement gives the storage capacity at a given pressure, which may exceed the actual gas content if the coal is undersaturated, and undersaturation means production begins only after pressure has been reduced substantially with no gas at all.

Finally, water is the operational and economic problem. CBM produces large water volumes, often of poor quality, and disposal cost is a major operating expense. Water production must fall for gas production to rise, and fields where water rates remain high have both a cost problem and a reservoir problem. Water sourcing, treatment, disposal permitting and cost frequently determine whether a CBM development proceeds.

By the end of this training, participants will be able to:

• Characterise coal as a reservoir including rank, composition, cleat systems and their properties
• Interpret adsorption isotherms and determine desorption pressure and storage capacity
• Determine gas content from desorption testing and assess its uncertainty
• Identify undersaturation and assess its consequences for development
• Analyse dual porosity flow including cleat flow and matrix diffusion
• Evaluate permeability behaviour including stress dependence and matrix shrinkage effects
• Predict the dewatering period and the characteristic gas production profile
• Design completions and stimulation appropriate to coal seams
• Forecast CBM well and field production and estimate reserves
• Assess water production, disposal requirements and their economic effect
• Evaluate enhanced coalbed methane recovery by CO2 or nitrogen injection

The training develops coal reservoir behaviour and then applies it through calculation and data interpretation. Participants interpret isotherms, calculate gas in place, assess saturation state, analyse production histories through dewatering and gas build-up, and forecast well performance. Permeability trajectory calculations demonstrate the competing stress and shrinkage effects. CBM field developments are examined for their production performance, water handling experience and economic outcome, including projects that failed on dewatering duration or water disposal cost.

Organisations sending participants to this training will:

• Evaluate CBM opportunities with correct understanding of the production profile
• Improve resource and reserves estimation through proper gas content and saturation assessment
• Plan water handling and disposal realistically before development commitment
• Improve well spacing and development design for dewatering efficiency
• Avoid development decisions based on early production data that misrepresents ultimate performance
• Assess enhanced CBM and CO2 storage opportunities in coal

Participants will:

• Understand why coal reservoirs behave as they do
• Interpret isotherms and gas content data correctly
• Forecast CBM production through dewatering and gas build-up
• Assess water handling requirements and their economic weight
• Estimate CBM reserves with appropriate evidence
• Build a specialist capability applicable to CBM and to CO2 storage in coal

• Reservoir engineers working coalbed methane assets
• Production engineers managing CBM wells and dewatering
• Development engineers evaluating CBM opportunities
• Reserves and evaluation engineers assessing coal resources
• Geoscientists working on coal characterisation
• Facilities and water management engineers on CBM projects
• Technical staff evaluating CBM and enhanced CBM projects

Upon successful completion of this training course, delegates will be awarded an official Certificate of Completion issued by the Petroleum Engineers Association (PEA), an ISO 9001:2015 certified training organization. The certificate carries 10 Credits and formally records the total learning hours completed.

Each certificate is signed by the Course Facilitator and the CEO of the Petroleum Engineers Association, and serves as verifiable proof of professional training that delegates can present to employers and professional bodies worldwide.