A scheduling model in capturing methane gas from methane clathrates deposits

Abstract

The execution of any project type, especially engineering-based projects, is usually time-based, efficiency-driven, and cost-effective. These factors are the deterministic parameters that engineer successful project completion. The application of scheduling models remains the best technique for achieving these three factors to their best degrees. Therefore, this study was centered on the impact study of applying the scheduling model in harvesting methane gas from methane clathrates deposits. Various data on gas hydrate reserves in the Niger Delta region of Nigeria were collected from relevant literature, studied, and analyzed. Such data includes the pictorial representation and description of the gas hydrate site in the Niger Delta region of Africa and various shapes and sizes of gas hydrate perimeters in the studied region positions of the gas reserves. The normal faults are projected on a bathymetric map of the study area and the bathymetric map of the Pockmark (with the stippled black line indicating the sea floor projection of a prominent N-S trending fracture in 3-D seismic data). As a type of scheduling model, the critical path method (CPM) was applied to develop the project’s work sequence using the activity on node (AON) architectural technique and Primavera P6 software after carefully identifying the primary operations involved in the project and their respective sub-operations or work breakdown structure (WBS). The risks associated with each operation were meticulously identified, with their consequent impact and exposure matrix determined using probabilistic measures of 1-5 according to the degree of the risk. Mitigation strategies were recommended for all the identified risks. The cost benefits of the project were X-rayed using parameters such as net present value (NPV), project payback time, internal rate of return (IRR), and net cumulative cash flow. From the results obtained, the CPM schedule showed that the project execution would last approximately ten months. All the operations involved in the project execution plan were all critical, proving that each activity should be completed within the scheduled run period. Else, the entire project would be affected. Also, risks with a high exposure matrix of 25, 12, and 4 were mitigated to 5, 3, and 0 using the recommended strategies. In addition, the project yielded an NPV of $20,736,951.04 for the run period of 22 years after the execution of the project, IRR of 14 %, and a payback time of 8 years (adding 2023- the year of project execution) provided the daily production rate is maintained within 60,000-65,000 MSCF/day. The cash flow and payback time will decrease if the daily production rate increases. Therefore, the application of CPM in extracting methane gas from gas hydrates positively affected the operation through the vivid insights provided in workflow pattern/methodology risks effects and cost benefits.