Mari Gas Field; discovered in 1957, is one of the oldest and mature fields of Pakistan and currently the highest gas producing field of the country. Mari Field has vital role in ensuring the food security of Pakistan as it is meeting gas needs of 87% of Fertilizer Industry. Field has been developed in multiple phases with 97 producing wells and complex gas gathering network of 284 km. In recent past few years, the country's supply and demand gap for gas is on widening trend. In order to support national energy needs, MPCL management decided to take initiative of executing gas incremental and optimization drive for playing its part in meeting the crucial energy demand of country. Furtermore, it was also matter of great importance to sustain the enhanced production plateau and meeting production & revenue targets.
Multidisciplinary teams were formed for evaluation of complete system from Reservoir to delivery end. Integrated approach was adopted for assessment of system at existing state of production and targeted production rate as de-coupled models would have not served the purpose well in this particular case. This study covers the integration of sub-surface and surface facilities; linking reservoir simulator at IPR Level, through in-house simulation model developed in commercial simulator. Keeping in view the target of study i.e. incremental and sustained production, reservoir rates were constrained and hence semi-implicit approach was used instead of fully implicit modeling which saved a lot of computation time and avoided complexities. Coupled model was simulated for predicting futuristic behavior of system at enhanced production which identified bottlenecks and integrity problems in existing system and also proposed the solutions through series of sensitivities analysis. This exercise triggered the proactive approach for solving system issues and kicked-off proper surveillance of system which are mandatory to sustain the desired production plateau and ensure the mechanical integrity of system. This study further emphasized that evaluation of complete system through integrated modeling can save compression cost at by de-bottlenecking the existing infrastructure.
At present, the field is producing at 20% incremental volume over and above of initial base volume and future plans have also been formulated to sustain the production plateau as per reservoir simulator.
CO2 capture and utilization (CCU) is currently a global topical issue, and is viewed as one possible route to reduction of CO2 concentrations in the atmosphere. The core issues of development, economy and the environment which the world faces in current times are identified to be dependent on the provision of clean, efficient, affordable and reliable energy services. Presently the world is highly dependent on fossil fuels for provision of energy services, and the amount renewable energies can sufficiently replace is minimal. The deployment of appropriate CO2 separation technologies for the processing of natural gas is viewed as an abatement measure towards global CO2 emissions reduction. Selection of the optimum technology among the several separation technologies for a particular separation need requires special attention in order to harness the economic and environmental benefits. The captured CO2 would also require appropriate disposal or utilisation so as to prevent or ‘delay’ its re-entry into the atmosphere. These challenges of CCU involving natural gas particularly during processing which has become an area of intense research shall be discussed in the paper with respect to the selected technique for CO2 capture. A typical natural gas production scenario in Nigeria shall be analysed for potential CO2 capture. Further discussion shall be on the identification of the recovered CO2 gas utilisation framework such as CO2 flooding (in Enhanced Oil Recovery) for additional revenue generation, assessment of the CO2 savings and the contribution to the clean development mechanism (CDM).
The explosive growth of shale gas production in the US has sparked a global race to determine which other regions from around the world have the potential to replicate this success. One of the main areas of focus is the Asia Pacific region, specifically Pakistan.
In this paper, real results from seven different US shale basins- Marcellus, Eagle Ford, Haynesville, Barnett, Woodford (West-Central Oklahoma), Fayetteville and Bakken- have been used to develop a comprehensive sequence of shale exploitation strategy for emerging shale plays. The study involves integration of shale gas exploitation knowledge reinforced by a decade of experience across most of the North American shale gas basins, with published data. Different reservoir properties have been compared to develop a comprehensive logic of the effective techniques to produce from shale-gas reservoirs. We have validated the sequence with real results from US shale production ventures, published case histories, and by global experts who have been directly involved in shale reserves evaluation and production.
Subsequently, several different reservoir attributes of Pakistan shale plays have been compared with US basins, in an attempt to identify analogues.
It is the intent of this paper to diminish the difficult and often expensive learning cycle time associated with a commercially successful shale project, as well as to attempt to illustrate the most influential factors that determine optimum production. A very few papers in the petroleum literature that provide an extensive and systematic approach towards shale exploitation strategy for given shale-reservoir conditions
Encouraged by the U.S. successful experience with shale plays, many Asia Pacific countries including China and India - having 1275 & 63 TCF of technically recoverable Shale gas respectively - have already started off with aggressive plans to exploit their vast shale reserves.
Pakistan is currently suffering an energy shortfall of 2.3 BCF and the energy demand is expected to increase further by 245% until 2022, as compared to 2008. As its conventional reserves deplete, there is a need to work on new frontiers of energy sources. Unconventional gas resources, such as shale gas, tight gas and coal bed methane, are the avenues that should be focused on, in the current scenario.
According to EIA estimates, Pakistan's total Risked Gas in Place is 206 TCF, while its Technically Producible Shale Reserves are 51 TCF. It is interesting to compare these postulations with the Sui gas field serving the energy needs of Pakistan for decades, and having an estimated original recoverable reserve of 12 TCF. However, efforts to develop this potential resource have been lacking perhaps due to the economic and technological challenges.