The Role of Well Testing in Improving the Productivity From a Thin, Tight, Fractured and Compartmentalized Limestone Reservoir

Zubari, Hisham; Al-Muftah, Ali Ebrahim; Qaseem, Naji Ahmed; Abdulwahab, Ayda

doi:10.2523/iptc-10278-ms

Cited by 9 publications

(3 citation statements)

References 3 publications

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“…Earlier attempts to conduct buildups in the gas lifted wells were complete failures due to the noise caused by the gas lift gas in the Early and Middle Time Region. So a new innovative procedure was designed to utilize the gas-lift gas at the wellhead to carry out a falloff test 5,6,7 . A known quantity of gas was injected into the formation over a few days followed by shutting in the well for a falloff test.…”

Section: Well-tests In Ahmadi Reservoirmentioning

confidence: 99%

Integrated Reservoir Connectivity Study of Ahmadi Fractured Reservoir in Bahrain Field

Al-Muftah

Murty²,

Lemaux

2009

SPE Middle East Oil and Gas Show and Conference

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This paper describes how the fracture model for Ahmadi was incorporated into a single and dual porosity simulation model. It highlights the approach and methodology that has been used for understanding the reservoir connectivity and its drive mechanism. In addition, the effect of dual porosity model in improving the initial history match of the reservoir performance and its recovery mechanism has been studied.The two Ahmadi carbonate reservoirs in Bahrain Field (Aa and Ab) are thin, highly faulted and irregularly-fractured. The complexity of these reservoirs has prevented an efficient recovery with average production of wells to 15 Bopd. This has prompted a detailed integrated study to fully understand the recovery mechanism and to increase the wells' productivity.A conceptual model has been developed for the reservoir connectivity of Ahmadi reservoirs by integrating static and dynamic data. This comprehensive study that integrates transient welltesting and production data with cores and image logs to map fracture network derived using seismic facies has resulted in improving the understanding of reservoir connectivity and flow mechanism. This was accomplished by building Discrete Fracture Model (DFN) that was tuned and validated using sector local well test models to match KH and pressure responses.In order to reduce uncertainties in the model, different scenarios were built for different fracture intensity and aperture to derive appropriate parameters to pass to reservoir simulator for full field simulation. DFN model output was used in both single and dual porosity models to obtain production performance of the reservoirs.

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Section: Well-tests In Ahmadi Reservoirmentioning

confidence: 99%

Integrated Reservoir Connectivity Study of Ahmadi Fractured Reservoir in Bahrain Field

Al-Muftah

Murty²,

Lemaux

2009

SPE Middle East Oil and Gas Show and Conference

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“…All these factors will result in lower recovery even with improved recovery processes or horizontal drilling. In the Bahrain Field 3D Seismic data was used to understand the anomalous production from a tight Carbonate reservoir through correlation of Transient Pressure Welltesting with fracture patterns derived from Seismic coherency maps 10 . Data from short term gas injection experiments in the field were used to verify the results (Figure :5).…”

Section: Carbonate Rocksmentioning

confidence: 99%

Challenges of Producing Middle East Oilfields During the Maturation Stage—A Paradigm Shift

Al-Mahroos¹,

Zubari²

2009

SPE Middle East Oil and Gas Show and Conference

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The Middle East oil fields provide an important energy source for the world. They hold two-third of the world oil reserves (Figure: 1, Table: 1), provide one-third of the world's oil supplies and have the highest Reserves to Production ratio in the world of 82 1 . Even though most of the Middle East oilfields are still prolific, many are already approaching the end of their primary stages as evident by increasing trends in water and gas productions. This is a natural process caused by maturation whereby a depleting oil reservoir looses its energy which results in oil productivity decline associated with intrusion of aquifer water and gas cap gas, when present. The challenge would be to transform the operation from Primary production to Secondary and Tertiary. This not only requires a change in the operation, but also a paradigm shift in reservoir management style and approach. This requires the identification of the pertinent issues and challenges that need to be resolved early and subsequently setting a roadmap plan to investigate, experiment and devise solutions. It also requires a quick, efficient and effective decision making process supported by modern corporate management style.In this paper we attempt to document the Primary to Secondary and Tertiary transition experience based on the 77 years old Maturing Bahrain Field which was the first oil discovery in the southern part of the Arabian Gulf. The paper does not discuss in detail the decision making process and the corporate management styles of mature field operation.

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“…In reality, naturally fractured reservoirs never have uniform distribution of fractures. The natural fractures occur in cluster or families of clusters oriented in particular directions (Zubari et al, 2005;Ozkaya and Richard, 2005;Sing et al, 2008). The reservoirs with non-uniform distribution of fractures are called partially naturally fractured reservoirs, PNFR (Qasem, 1996;Qasem et al, 2002;.…”

Section: Introductionmentioning

confidence: 98%

Pressure Transient Behavior of Partially Naturally Fractured Reservoirs

Qasem

2016

Day 2 Wed, March 23, 2016

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Naturally fractured reservoirs (NFRs) always have flow networks that are more or less irregular, discontinuous, or clustered. NFR with such spatially non-uniform distribution of fractures is called partially naturally fractured reservoir (PNFR). An improved understanding of pressure response is required to characterize PNFR. This paper presents a better understanding of well test pressure response of PNFR.Stochastic modeling was used to generate various geological models with different fracture intensities. Single phase liquid flow through stochastically generated reservoirs is simulated by a numerical reservoir simulator. Dual-porosity / dual-permeability model was selected to simulate PNFR. A vast database of pressure transient responses of the reservoirs with varying fracture intensity, matrix permeability and fracture porosity is presented in this paper. Pressure derivative was used to analyze the pressure transient responses.Pressure derivative analysis indicates multiple V-shapes representing various sets of fracture intensities. It is observed that with the increase of fracture porosity V-shape become more pronounced. It is also observed that with the increase of matrix permeability, the duration of composit radial flow is prolonged. The shapes of pressure drawdown plots indicate the level of fracture connectivity of the reservoir. Whereas the fracture connectivity is related to the fracture intensity (FI). The critical value of fracture intensity is observed around 60 percent which results in the formation of connected fracture network.The interpretation of pressure responses of PNFR becomes very difficult and challenging because the available simplified models do not relate to reality of reservoirs. This paper quantifies the fracture intensity for a broad range of PNFR with the use of pressure transient responses. This quantification is a major contribution to the present literature.

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The Role of Well Testing in Improving the Productivity From a Thin, Tight, Fractured and Compartmentalized Limestone Reservoir

Cited by 9 publications

References 3 publications

Integrated Reservoir Connectivity Study of Ahmadi Fractured Reservoir in Bahrain Field

Integrated Reservoir Connectivity Study of Ahmadi Fractured Reservoir in Bahrain Field

Challenges of Producing Middle East Oilfields During the Maturation Stage—A Paradigm Shift

Pressure Transient Behavior of Partially Naturally Fractured Reservoirs

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