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Collaborating Authors
Amjad, Muhammad
Rejuvenating Profitability and Performance of Aging Gas Field through Multi-Pronged Strategy: System De-Bottlenecking, Well Optimization and Opex Management
Awase, Azar (United Energy Pakistan Limited, Karachi, Sindh, Pakistan) | Memon, Sikandar Ali (United Energy Pakistan Limited, Karachi, Sindh, Pakistan) | Zafar, Jahangeer (United Energy Pakistan Limited, Karachi, Sindh, Pakistan) | Khan, Zaeem Hasan (United Energy Pakistan Limited, Karachi, Sindh, Pakistan) | Noman, Muhammad (United Energy Pakistan Limited, Karachi, Sindh, Pakistan) | Ejaz, Muhtashim (United Energy Pakistan Limited, Karachi, Sindh, Pakistan) | Ali, Mushtaque (United Energy Pakistan Limited, Karachi, Sindh, Pakistan) | Amjad, Muhammad (Prime International Oil and Gas Company, Karachi, Sindh, Pakistan) | Sirati, Muhammad Attar (Pakistan Petroleum Limited, Karachi, Sindh, Pakistan)
Abstract This paper presents a success case of optimizing a challenging mature gas field, producing at tail-end, with low reservoir pressure and increasing water gas ratio trend, complex surface network, and high operating cost. The situation demanded cost efficiency, novel strategies to optimize production and prudent decisions to safeguard reserves and sustain production. S-Field was put on production in 2003 and peaked production of 460 MMscfd in 2007. In 2021, reservoir pressure dropped from 5400 to 300 psi, wells became critical and front-end compressors approached lower limits. Additionally, field was close to economic threshold, owing to late life conditions and high Opex. An integrated approach was taken to mitigate the challenges. A network modeling exercise with multiple sensitivities were performed to simulate the application of different deliq techniques (soap sticks, velocity string, CSI) and operating field with expanded compressor envelop. Subsequently, the strategy was implemented in phases to optimize the field. Simulations performed for no further activity case with prevailing production technical limit suggested additional recoveries of only 4 Bscf for one year remaining. The simulated optimization cases predicted additional recoveries of around 20 Bscf with field life extension by 5 years. On top of production and reserves, the strategy envisaged significant improvement in field profitability by saving fuel gas (โผ1 Bscf annual) and maintenance cost (2.5 $MM annual). The capital investment for the project was $10MM, with estimated project NPV of $17MM. The project implemented in Oct 2021 with optimized compression scheme, smaller tubing size, velocity strings, and cost-effective foam injection. The actual field delivery was vigilantly monitored and till day additional volumes of 8 Bscf have been materialized and field is demonstrating very stable performance, closely matching the premise. A novel aspect is that brown fields may be rejuvenated by expanding techno-commercial boundaries besides application of optimization techniques. At the stage where many operators would consider abandoning the fields, results driven strategy coupled with multidisciplinary inputs resulted in higher profits and additional recovery.
- North America > United States > Texas > Kleberg County (0.24)
- North America > United States > Texas > Chambers County (0.24)
Successful Analytical Modeling of a Complex Dry Gas Field to Identify Potential Infill Opportunities
Syed, Rafiah (United Energy Pakistan Limited) | Ejaz, Muhtashim (United Energy Pakistan Limited) | Azeem, Abdul (United Energy Pakistan Limited) | Mehmood, Saad (United Energy Pakistan Limited) | Amjad, Muhammad (Prime Pakistan Limited) | Sirati, Muhammad Attar (Pakistan Petroleum Limited) | Ashraf, Zaid (OGDCL) | Yousaf, Haleem (OGDCL)
Abstract The objective of the study is analytical modeling of a dry gas reservoir, with more than 30 drilled wells and 15+ years of production history, underlain by thick tight gas zone, that is highly compartmentalized (both structural and stratigraphic) and heterogenous (laterally and vertically). The multi tank material balance model is created to address the major uncertainties within the compartments such as Fault Transmissibility, Aquifer Strength, Early Water Influx, Tight Gas Support, and its quantification by the integration of all the geological, fluid, rock, pressure, and the production data. Some of the structurally up-dip wells are watered out however down-dip wells continue to produce gas at reasonable rates with complete stability in the reservoir pressure. The model has been history matched with multiple scenarios and showed that the pressure recharging observed in a certain compartment is from an additional GIIP feeding into the compartment through the underlying tighter zone rather than laterally from the other compartments. A weak aquifer encroachment in the same compartment is from an adjacent compartment having moderate water drive through fault breach. Compartments are history matched with adequate pressure and Water Gas Ratio (WGR) by manipulating productivity indices for individual wells, modifying aquifer strength, inter-compartment transmissibility, pseudo relative permeability curves and impact of tight gas recharging. The quantitative estimation of minimum connected GIIP is performed by balancing the support through encroaching aquifer and tight gas recharging. The scope included the estimation of the minimum connected Gas Initially in Place (GIIP), ascertain aquifer strength and direction as well as pressure recharging within the different compartments using pressure and production data. The study assisted in capturing the communication between the compartments and evaluation of remaining potential of the field. The results would then be used in subsequent numerical modelling with the possibility of increasing overall recovery from the field.
Successful Well Placement at a Down-Dip Location for Recovery Optimization in a Complex Water Drive Compartment โ A Case Study of a Mature Gas Field
Ejaz, Muhtashim (United Energy Pakistan Limited, Karachi, Pakistan) | Azeem, Abdul (United Energy Pakistan Limited, Karachi, Pakistan) | Salman, Khursand (United Energy Pakistan Limited, Karachi, Pakistan) | Ashraf, Zaid (Oil & Gas Development Company Limited, Islamabad, Pakistan) | Akram, Shahbaz (Oil & Gas Development Company Limited, Islamabad, Pakistan) | Amjad, Muhammad (Prime Pakistan Limited, Karachi, Pakistan) | Sirati, Muhammad Attar (Pakistan Petroleum Limited, Karachi, Pakistan)
Abstract The paper is based on successful well placement in a mature gas field located in Middle Indus basin. The well was placed at a down-dip location in a water-drive compartment and yielded positive results. The paper provides comprehensive understanding of compartmentโs complex dynamics, subsequent reservoir modelling, well location optimization and post well results. Identification of infill location in the compartment of interest was challenging due to complicated dynamic behavior described by water encroachment and pressure re-charging mechanisms. The compartment has observed unusual water encroachment where water breakthrough occurred initially in up-dip wells. When analyzed in synergy with adjacent compartment, this unorthodox water encroachment mystery was resolved. In addition, the compartment has also observed significant gas pressure recharging from underlying tight sands. In fact, the compartment has produced substantially higher than its initial gas in-place implying enormous potential in these tight sands. Therefore, the infill well was planned with the aim to exploit this tight sand via conventional sand. These above-mentioned understandings complemented in dynamic modelling which was accordingly history matched and subjected to sensitivity runs for location optimization. Forecast performed at different well locations helped in the identification of sweet spot at downdip location which ensured maximum recovery. Subsequently down-dip location was preferred for drilling. Post well results came as per premised and validated pre-drill understanding of the compartment. Successful wells result provided sustainability to overall field production. In addition, it also helped in consolidating confidence in tight sand potential and its gas support and has provided further infill drilling opportunities. The paper highlights the significance of utilizing all available historical datasets and conventional analyses to resolve an unorthodox problem which apparently depicted no further potential and development opportunity in an asset where significant resources were still to be exploited. The workflow adopted helped in de-risking the opportunity and identifying optimum location for downdip well placement against the intuition and general understanding.
- Asia > Pakistan (1.00)
- North America > United States > Texas > Coleman County (0.25)
- North America > United States > Texas > Anadarko Basin (0.99)
- North America > United States > Oklahoma > Anadarko Basin (0.99)
- North America > United States > Kansas > Anadarko Basin (0.99)
- Reservoir Description and Dynamics > Reservoir Simulation (1.00)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Conformance improvement (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Exploration, development, structural geology (0.94)
- Management > Asset and Portfolio Management > Field development optimization and planning (0.90)
ABSTRACT Widening supply and demand gap in natural gas industry, the advent of tight gas policy and increasing interest of operators in tight gas sands and shale has opened new venues for development of unconventional plays in Pakistan. Middle Indus Basin hosts important gas fields of Pakistan. Most of the wells in this basin are completed in conventional lower Goru Sands. Lower Goru formation consists of inter-bedded sequences of sands and shale. Its unconventional sand and shale plays hold immense potential which has not yet been exploited due to lack of technology and promising economics. Moreover, Sembar shale is the well known source rock in this basin holding large shale gas potential. GIIP estimates for Lower Goru tight sands excluding the shale prospects are 8.4 TCF which are considered pessimistic due to lack of data in many fields. From the currently suspended or abandoned wellbores of the Middle Indus Basin, a pilot project needs to be defined in each of the fields, to prove the technical and economical feasibility of tight Gas Potential of the Basin. Commencement of production from unconventional sands will enhance the production in a cost effective manner due to availability of infrastructure and facilities. This paper focuses on the utilization of existing wellbores as well as data set and highlighting additional data acquisition requirements coupled with completion and multi-stage fracturing techniques for designing a pilot project. Case study of a pilot project in one of the fields of this basin is discussed. It encompasses the basic workflow, candidate selection criterion, Geo-mechanics, sector modeling, hydraulic fracture design and risk evaluation coupled with its use in full field development projects.
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Sandstone (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (1.00)
- Asia > Pakistan > Sindh > Lower Indus Basin > Goru Formation (0.99)
- Asia > Pakistan > Sindh > Khairpur District > Indus Basin > Kadanwari Field (0.99)
- Asia > Pakistan > Sindh > Sanghar District > Sembar Formation (0.98)