How We Shortlisted Compression Options for a $1bn+ Field Development — Step by Step
When you're evaluating compression concepts for a billion-dollar field development, the stakes are too high for gut feel and vendor brochures.
One wrong call can lock your client into hundreds of millions of unnecessary CAPEX — or worse, a configuration that underperforms across the full field life.
This is exactly the challenge we faced on a gas-condensate field for an international operator. And it's why we developed the CONCEPTCOMPRESSOR™ framework — a five-step process for systematically selecting the optimal gas compression solution.
In this article, I want to walk you through Step 3: Shortlist Analysis — the most analytically demanding step in the process, and often the one that separates a defensible investment decision from an expensive regret.
What Is Step 3 — And Why Does It Matter?
By the time you reach Step 3, you've already:
Step 1 (Opportunity Identification): Mapped the field's production profile and compression requirements across the full field life
Step 2 (Options Analysis): Screened a broad long-list of development concepts — in the international operator’s case, eleven distinct options ranging from pure cluster compression to hybrid and centralised solutions
Step 3 is where you take the two or three highest-performing options and put them through rigorous, detailed scrutiny. This isn't a high-level screening anymore. It's the analysis management will use to make a Final Investment Decision.
The four pillars of Step 3 are:
CAPEX/OPEX Estimation
NPV and IRR Analysis
Risk and Sensitivity Analysis
Operability Review
Let me show you what that looked like in practice — and what we found.
The Two Options That Made the Shortlist
After the Step 2 screening, two frontrunners emerged from eleven initial concepts:
Hybrid Compression Option (Cluster + Central) A distributed architecture with compression at well clusters supplemented by a central facility.
Central Compression with Additional Pipelines Option: A single centralised compression facility gathering production from multiple reservoir streams via an expanded pipeline network.
On the surface, the Hybrid Compression option seemed like the sensible choice — spreading infrastructure across the field and providing better pipeline operation and management ability. The Central+pipelines option looked more unworkable. The analysis told a very different story.
Pillar 1: CAPEX/OPEX Estimation
The first task was developing credible cost estimates for both options — not vendor quotes, not ballpark figures, but properly built-up estimates accounting for equipment, installation, infrastructure, and operating costs across the full field life.
Hybrid Option: $1,896M CAPEX
Central Option: $1,152M CAPEX
Difference: $744M lower
That's not a rounding error. Central Option carried a CAPEX that was nearly $750 million lower than the hybrid configuration. The centralised approach eliminated the duplication of equipment, infrastructure, and manning that comes with distributed cluster compression.
But CAPEX alone never tells the full story. We needed to understand the true economic value of each option over the life of the field.
Pillar 2: NPV and IRR Analysis
This is where the Shortlist Analysis really earns its keep. Rather than just comparing upfront costs, we modelled the full-lifecycle economics of each option — discounted cash flows, phased capital expenditure, operating expenditure over field life, and revenue generation.
Hybrid Option: $1,760M NPV
Central Option: $2,200M NPV (IRR 32%)
Central option delivered an NPV $440 million higher than the hybrid configuration — a 25% improvement. The centralised solution wasn't just cheaper to build; it was more valuable over the life of the field.
The 32% IRR on the recommended solution represented excellent returns and gave management the commercial confidence to proceed.
Pillar 3: Risk and Sensitivity Analysis
Strong base-case economics mean nothing if the solution falls apart under realistic uncertainty. Step 3 requires stress-testing both options across the key variables that drive project outcomes.
For this project, we tested sensitivity to:
Production upside and downside scenarios — higher and lower reservoir deliverability than the base case
Reservoir decline rates — early versus late field pressure decline
Capital cost escalation — what happens if CAPEX runs over?
Operating cost variability — manning, energy, maintenance
The central compression option demonstrated greater robustness across these scenarios. The hybrid option's economics were more sensitive to production variability — because poor performance at any individual cluster had a disproportionate impact on overall field economics. The centralised design, by contrast, benefited from economies of scale and phased expandability that protected returns across a wider range of outcomes.
Pillar 4: Operability Review
This is the step that technical studies most often shortchange — and the one that operators are most grateful we included.
Centralised compression raised legitimate questions that had to be answered before shortlisting could be completed:
Could a single facility practically manage three distinct reservoir streams with different pressure profiles?
Were the logistical and access requirements achievable in this specific geographic and environmental context?
What were the implications for manning, maintenance, and emergency response?
We found that a centralised facility — designed with appropriate separation trains for each reservoir stream, modular expansion capability, and a phased implementation strategy — was not only operationally viable but preferable. Centralising the facility also reduced the need for helicopter traffic and avoided infrastructure development in environmentally sensitive protected areas. These were not afterthoughts; they became strategic advantages.
The hybrid option, by contrast, created a more complex operational footprint — multiple compression sites to maintain, staff, and optimise simultaneously.
The Shortlist Outcome
The Step 3 analysis produced a clear recommendation: Central Compression with Additional Pipelines Option.
The case was compelling on every dimension:
✅ $744M lower CAPEX vs. the hybrid option
✅ $440M higher NPV (25% improvement)
✅ 32% IRR — excellent project returns
✅ More robust across risk and sensitivity scenarios
✅ Operationally superior — centralised, maintainable, environmentally sustainable
This wasn't a close call in the end. But without the rigour of Step 3 analysis, the hybrid option's superficial appeal — spread the risk, don't put all your eggs in one basket — could have led to a very different, and very costly, decision.
Why Most Evaluations Get This Wrong
In our experience, compression selection studies fail at the shortlist stage for a handful of recurring reasons:
They stop at CAPEX. NPV and IRR are non-negotiable. A solution with higher upfront cost can — and often does — deliver superior returns. You cannot know this without the full lifecycle analysis.
They skip the sensitivity analysis. Base-case economics that look attractive can deteriorate rapidly under realistic downside scenarios. If your recommendation doesn't hold up under stress-testing, it isn't a recommendation; it's a bet.
They treat operability as an afterthought. Options that look optimal on paper frequently fail in practice because they haven't been evaluated against real-world operational constraints. Operator input must be embedded in the shortlist process, not bolted on at the end.
They rely on vendor input at this stage. Vendors optimise for their own capabilities, not your field. Independence matters.
What Comes Next in CONCEPTCOMPRESSOR™
The Shortlist Analysis feeds directly into:
Step 4: Concept Proof — integrated asset modelling to validate the recommended option across all life-of-field scenarios, including equipment outages, operational transients, and varying reservoir decline profiles
Step 5: Development Roadmap — a phased implementation plan that matches capital expenditure to revenue generation, with clear milestones and flexibility built in
On this international operator’s project, Phase 1 compression trains were successfully installed and operational on schedule. The asset has been delivering against its targets ever since.
Join Us at the Live Workshop — 25 March 2026
We're running a live, interactive workshop —"Shortlisting for Success: A Tactical Approach to Selecting the Right Compression System" — where we walk through the CONCEPTCOMPRESSOR™ methodology in detail, using this case study as a worked example.
By the end of the session, you will:
Understand the critical factors that differentiate optimal from suboptimal compression solutions
Learn the full 5-step CONCEPTCOMPRESSOR™ framework for systematic evaluation
See real-world application through this $750M CAPEX reduction case study
Walk away with actionable strategies you can apply to your projects immediately
This workshop is designed for Project Managers, Development Managers, Engineering Managers, and Engineers leading or contributing to compression field development studies.
📅 Date: 25 March 2026 🔗Register here: https://events.teams.microsoft.com/event/ba659867-4760-47c0-bd7a-9865f2ebf7ef@688191e1-fe7b-4973-8a41-59dec98582c9
Spaces are limited. If you're working on a compression field development — or about to be — this is the session to attend.
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Sodi Toby is a Chartered Engineer (CEng) and Fellow of the Institution of Mechanical Engineers (FIMechE), and Managing Director of Eta Energy Solutions. Eta Energy Solutions bridges the gap between Oil & Gas Operators and OEMs, helping medium-sized companies maximise plant uptime and boost revenue through optimised gas compression solutions.
📧 info@eta-energy.co.uk | 🌐www.eta-energy.co.uk | 📞 +44 (0)1273 921 037
