Bo Feng

Surface-facility construction in tight gas fields is capital-intensive and generates environmental impacts that span the entire life cycle, making it a critical focus for the low-carbon transition. Building on Life Cycle Analysis (LCA) and Life Cycle Cost Analysis (LCCA), this study develops a fuzzy Multi-Criteria Decision Analysis (MCDA) framework that simultaneously accounts for environmental, cost, and technical factors, thereby providing a full-life-cycle optimisation pathway for process selection.

The analysis first delineates the “well–gathering station–processing plant–pipeline network” system boundary. An LCA model constructed in SimaPro quantifies Global Warming Potential (GWP), Human Toxicity Potential (HTP) and Abiotic Depletion Potential for Elements (ADPE). These metrics are paired with an LCCA-based economic appraisal to devise phase-specific optimisation strategies for construction, operation and decommissioning. An  "Environmental-Cost-Technical" multi-objective decision model is then established. Subjective weights are obtained with the Triangular Fuzzy Analytic Hierarchy Process (TFAHP); objective weights are derived with the Criteria Importance Through Intercriteria Correlation (CRITIC) method; and composite weights are calculated by minimum-deviation estimation. The Multiple-Attribute Boundary Approximation area Comparison (MABAC) method is finally used to rank alternative surface-engineering schemes.

Applying the framework to the Sulige gas field shows that the optimal configuration is “downhole throttling, multi-well manifolding, wet-gas transmission, two-stage compression, centralised processing”. During construction, integrated skid-mounted equipment cuts GWP key-factor emissions by 6.8% and HTP risk by 22.5%; in operation, green-power drives and VOC recovery reduce GWP key-factor emissions by 27.4%, HTP risk by 31.9% and ADPE consumption by 9.5%; at decommissioning, a standard steel-recycling system achieves an 80% steel recovery rate.

By quantifying environmental and economic impacts through coupled LCA-LCCA and embedding them in a fuzzy MCDA framework that addresses life-cycle cost and technical feasibility, this study offers a replicable pathway for the sustainable development of surface facilities in tight gas fields.

Co-author/s:

Ruoqi Tan, Changqing Engineering Design Co., Ltd, National Petroleum Corporation (CNPC).

Jiaming Yu, Changqing Engineering Design Co., Ltd, National Petroleum Corporation (CNPC).

Guotao Fan, Changqing Engineering Design Co., Ltd, National Petroleum Corporation (CNPC).

Rui Zhang, Changqing Engineering Design Co., Ltd, National Petroleum Corporation (CNPC).

Zhenfang Xu, Changqing Engineering Design Co., Ltd, National Petroleum Corporation (CNPC).