Project Overview

An operator considering a programme of well reactivations and sidetracks in a mature onshore field engaged SPD to conduct a technical and economic feasibility study before committing any capital. Several wells had been shut in for extended periods due to downhole damage, and the subsurface team had identified potential bypass targets that could be accessed through low-cost sidetrack operations. The operator needed an independent assessment of which wells were genuinely viable candidates, what the technical risks were, and whether the economics justified proceeding.

Key Challenges

• Well conditions uncertain — extended shut-in periods and incomplete workover records meant downhole status could not be confirmed without investigation
• Multiple potential targets with varying degrees of reservoir confidence — from well-defined offset analogues to highly speculative conceptual prospects
• Technical feasibility and economic viability needed to be assessed simultaneously — a technically achievable sidetrack that did not meet the economic hurdle was of no value
• Market conditions creating pressure to pursue the lowest-cost intervention option in every case, requiring rigorous comparison of sidetrack methods and rig versus rigless options

SPD’s Approach

SPD developed a structured screening matrix assessing every candidate well against technical feasibility criteria — wellbore access, through-bore diameter, deviation profile, cement integrity and downhole obstruction risk — ranked against a defined viability threshold. Wells that did not meet the technical threshold were eliminated at the screening stage with documented rationale.

For each viable candidate, SPD produced a technical concept design, a risk register addressing specific downhole and operational uncertainties, and a cost estimate at ±30% accuracy. Economic modelling was performed using the operator’s production assumptions, producing a ranked list of opportunities by NPV and risk-weighted return. The final report identified the three highest-priority candidates with a recommended execution sequence, a pre-execution data acquisition plan and a decision framework for go/no-go as conditions evolved.

Results & Value Delivered

• Capital protected — screening eliminated non-viable candidates before detailed engineering spend, protecting the operator from technically flawed opportunities
• Three priority candidates identified — ranked list with supporting technical designs and economic analysis gave a clear, evidence-based basis for capital allocation
• Risk explicitly quantified — well-specific risk registers gave transparent view of residual uncertainty before execution
• Execution sequence optimised — recommended sequencing reduced programme cost by managing rig mobilisation and logistics
• Executed wells performed above forecast — technical design quality and pre-execution data acquisition contributed to above-forecast production on both executed wells