Reservoir characterization is a key element of asset evaluation and optimal field development strategies. Accurate water saturation evaluation and permeability profiling are crucial parameters in determining volumetrics and productivity of the multiple, stacked carbonate reservoirs in offshore Abu Dhabi and derisking the reservoir management process. The main objective of this paper is to look at saturation and permeability interpretations by comparing the various static and dynamic logging measurements. Archie in 1942 postulated the water saturation calculation equation for sandstones, but it has also been used in carbonates because of its simplicity. Multiple authors have understood the effect of different textural parameters on water saturation calculation and have come up with different workaround techniques. The current case study illustrates how the integration of static measurements, such as dielectric dispersion and nuclear magnetic resonance (NMR) with dynamic measurements improves our understanding of the reservoir properties (saturation and permeability), and in turn support a more accurate reservoir evaluation. Sampling and downhole fluid analysis (DFA) performed by the wireline formation tester (WFT) identifies the fluid and rock properties in the various flow units. One key observation in this case study is how the conventional Archie-based equation has struggled to provide satisfactory and accurate water saturation results in this reservoir, whereas the dielectric dispersion measurement proves its value by providing direct water volume measurement that is validated with the fluid pressure gradient and the sampling results. The WFT sampling and DFA stations—which account for the flowing fractions and the hydrocarbon characterization—are followed by an extended build up, otherwise known as mini drill stem test (mini-DST). The radial flow regime is used to derive the horizontal/radial permeability across the tested interval. Mini-DST measurements provide a depth of investigation much deeper into the reservoir compared to standard core or log analysis, yet at a fraction of the operational times typically needed by a full drill-stem test. This integration of static (saturations and permeability) with dynamic measurements (DFA and Mini-DST) aids in providing accurate reservoir characterization and better understanding of its properties. Multifrequency dielectric measurements add a weapon in the arsenal of the petrophysicist and can be used in conjunction with dynamic measurements from the wireline formation tester to understand the rock and fluid properties and get a better understanding of the Cretaceous reservoirs of interest in offshore Abu Dhabi.

The technological advances in oil and gas industry are enabling the operating companies to monitor their hydrocarbon reservoirs closely. Today reservoir surveillance engineers are able to acquire more well/reservoir performance data than in the past. Multi-Phase Flow Metering is an expedient addition in production testing domain. As per the recent statistics, globally, approximately 4000 Multi-Phase Flow Meters (MPFM) installations are providing reliable measurements under different applications. As with any new technology the philosophy behind MPFM measurements is blurry for many users, who find difficulty establishing and implementing the appropriate data validation workflows on the MPFM data. The conventional production test data validation approach can be applied to the MPFM measurements up to a certain extent, but in order to find the source of discrepancies in MPFM data, additional processes are required to be included in the workflow. The production history of the majority of hydrocarbon reservoirs in the world was built on conventional test separator flow rate data. Introducing a new measurement technology with different set of accuracies and different working principles has been a challenge for the production data users. To standardize the data validation process, a systematic approach can be implemented to validate the production testing data from different sources, which not only will help the end users to gain confidence in MPFM flow measurements but also will assist identifying the sources of discrepancy in MPFM measurements during day to day operations. This paper will explain the stepwise data validation approach that can benefit different production test data users in oil and gas industry.

Generally the hydrocarbon recovery factor and the complexity of the recovery mechanism are directly related. With the maturation of a producing field, enhanced monitoring plans and the implementation of fit-for-purpose data analyses workflows become necessary to understand well and reservoir dynamics for adequate reservoir management decisions. However, in reality, shifting the paradigm to adopt appropriate work strategies can, in certain circumstances, be restrained by several factors, including organizational issues.In this paper, the risk of implementing simplified reservoir management practices in a complex carbonate field is evaluated. An extensive study carried out in a thin oil-rim carbonate reservoir which undergoes substantial gas and water injection in its huge gas cap and aquifer respectively. The objective of the study is to review the use of conventional lift curves i.e., oil rate -well head pressure cross plot, to: a. Predict well performance changes under varying production conditions. b. Accurately allocate daily well production. It is found that the use of a simplified approach for well performance analyses and production allocation may not be representative in this particular case. The potential risks of using simplified approach are identified and the need of adopting sophisticated processes, to carry out appropriate modelling for representative results, are also discussed in this work.This study conceptually demonstrates that a fully integrated reservoir/well/network coupled model is required to accurately address such cases. An integrated approach would not only benefit better understanding of well and reservoir behavior, but it would also aid meaningful decisions for establishing reservoir management best practices and strategies.

During the initial development phase of a new field operated by Abu Dhabi Marine Operating Company (ADMA-OPCO), due to the unavailability of processing facility, produced fluid is designed to flow into a pipeline operated by Zakum Development Company (ZADCO). The produced fluid is metered using two Custody Transfer Multi Phase Flow Meters (MPFM) with a normal operating philosophy of one-operating-one-standby and can be operated in series for verification purposes. This paper discusses the operational challenges for the custody transfer of ADMA fluid to ZADCO processing plant. The challenges discussed in this paper are due to low production during commissioning and commingled production from multiple reservoirs. During commissioning of the production platforms, the production was lower than the operating envelope of the meter. This would result in significant error in the meter readings. Since there was physical separation between the production facility and the metering is about fifteen kms away, the time lag between the meters and the production platform did cause further uncertainty in the measurement. To overcome this challenge a strategy was developed to meter the produced fluid with most accurate meters as available at each stage with consensus from both parties. The commingled production from three reservoirs with significant difference in parameters posed challenge for the use of appropriate PVT properties in the custody transfer MPFMs for the conversion from line condition to standard condition. This was overcome by performing sensitivity analysis on the mixtures, developing PVT tables for commingled production ratios based on reservoirs and implementing a process on the selection of the appropriate table based on the changes in production contribution from the different reservoirs. Other minor operational issues related to the MPFM metering are also discussed in the paper.

Operational efficiency improvement is a fundamental requirement and the continuous effort to achieve it is the inevitable need for any organization that targets profitable throughput in today's volatile market. Based on a study for a group of North American oilfields, in a typical mature oilfield, on an average 6% to 10% production deferments are caused by the process inefficiencies. Organizations continuously look for cost effective technologies that can facilitate implementing systematic operating procedures to maximize value of available resources and to provide a controlled environment for executing defined activities efficiently. Business process management (BPM) is a technique that brings in a governance mechanism to the efficient execution of processes. It uses various methods to discover, model, analyze, measure, improve, optimize, and automate business process to generate and track improvement actions. A typical project implementation involves a holistic review of the existing processes, identifications of the bottlenecks, mapping of the stakeholders and developing definitions for efficient corrective actions that enable closing system gaps. Early engagement with the stakeholders and an insightful management of change (MOC) are the key requisites of assuring the successful process roll out. Despite many industries, such as, medical and financial institutions, human capital management firms and logistics tracking system providers, have exploited the use of BPM and workflow automation to enhance their operation management capabilities, oil and gas industry still lags behind in capitalizing the benefits of this useful combination. This paper demonstrates the stepwise approach of implementing effective strategies, methods, and techniques to model and roll out collaborative solutions to help multi-disciplinary teams to execute business processes efficiently and consistently, whilst ensuring adherence to standards and agreed guidelines for maximizing efficiency and profitability. A real implementation case is presented, where a complex integrated production management and optimization system is managed leveraging workflow automation and BPM that has resulted in significant efficiency gain.