The evidence arrives after the decision has been made many times. A spacing test drilled today produces interference evidence over the following one to three years, by which time a development programme operating on the original assumption may have drilled dozens of wells. This asymmetry is the central difficulty: spacing must be chosen before the evidence exists, and the cost of being wrong scales with programme size. Staged development, where spacing is tested early and the programme adjusts, is the practical response and is frequently overridden by the pressure to maintain drilling activity.

Recovery per well and recovery per section point in opposite directions. Wider spacing maximises the recovery from each well and the return on each well's capital. Tighter spacing maximises the recovery from the acreage and the total volume produced. Which matters depends on whether the constraint is capital or acreage, and on the discount rate: acceleration has value, so tighter spacing that produces the same volume sooner can be worth more even without additional recovery. Framing the decision correctly is as important as the technical work behind it.

Parent-child effects have become the dominant infill problem in unconventional development. Producing a parent well lowers pore pressure around it, which reduces the local stress and steers a child well's fractures toward the depleted region. The child well underperforms because its fractures grew into rock that has already been drained, and the parent well is frequently damaged by fluid and proppant entering it. The industry has accumulated substantial evidence on this, and the mitigations, though imperfect, are well established.

Finally, infill decisions in mature conventional fields have a different character. There the question is whether remaining oil exists in locations that current wells do not drain, which requires mapping remaining saturation rather than testing interference. Streamline analysis, saturation logging, material balance by region and simulation all contribute, and the answer is frequently that a small number of well-placed infills deliver most of the available value.

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

• Determine drainage area and contacted volume using pressure, production and tracer methods
• Design spacing tests that will resolve the spacing question within a useful timeframe
• Interpret spacing test results including interference evidence and well performance comparison
• Evaluate the trade-off between recovery per well and recovery per section
• Assess depletion effects on infill well performance including pressure and stress changes
• Diagnose frac hits and parent well damage from production and pressure evidence
• Quantify child well underperformance and its causes
• Specify mitigation measures including sequencing, pressure management and completion design
• Identify infill candidates in mature conventional fields from remaining oil evidence
• Determine optimum well density on an economic basis including acceleration value

Organisations sending participants to this training will:

• Improve capital efficiency by selecting well density on sound technical and economic grounds
• Reduce infill well underperformance through better parent-child management
• Reduce parent well damage during infill operations
• Design spacing tests that resolve the question before large programmes commit
• Improve infill candidate selection in mature conventional fields
• Avoid repeating a spacing error across an entire development programme

Participants will:

• Determine drainage and contacted volume from available data
• Design and interpret spacing tests
• Diagnose interference and parent-child effects
• Specify mitigation and sequencing strategies
• Frame spacing decisions economically rather than only technically
• Contribute to the decision with the largest cumulative capital consequence in a development

• Reservoir engineers working on development planning
• Development and asset engineers determining well counts and spacing
• Completion engineers designing infill and protective completions
• Production engineers managing parent wells during infill operations
• Reserves and evaluation engineers assessing undeveloped locations
• Technical staff evaluating development programmes and acquisitions
• Asset managers approving development capital

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.