scholarly journals Structural Reservoir Characterization of Akkas Gas Field, Western Iraq: Implications for Hydrocarbon Recovery

2021 ◽  
pp. 4769-4778
Author(s):  
Abdulkhaleq A. Alhadithi
Keyword(s):  
Reservoir Characterization ◽  
Gas Production ◽  
Secondary Porosity ◽  
Gas Field ◽  
Horizontal Drilling ◽  
Hinge Line ◽  
Hydrocarbon Recovery ◽  
Fracture Surfaces ◽  
Bedding Planes ◽  
Brittle Sandstone

     Akkas Field is a structural trap with a sandstone reservoir that contains proven gas condensate. The field is a faulted anticline that consists of the Ordovician Khabour Formation. The objective of this research is to use structural reservoir characterization for hydrocarbon recovery. The stratigraphic sequence of the Silurian and older strata was subjected to an uplift that developed a gentle NW-SE trending anticline. The uplifting and folding events developed micro-fractures represented by tension cracks.  These microfractures, whether they are outer arc or release fractures, are parallel to the hinge line of the anticline and perpendicular to the bedding planes. The brittle sandstone layers of the reservoir are interbedded with ductile units of shale. The sandstone layers accommodate the formation of micro fractures that play a major role to increase the secondary porosity. The gas and condensate have been stored mainly through the micro fractures. Two types of drilling have been used for experimental gas production, vertical and horizontal. Horizontal drilling was parallel to both hinge line of the anticline and micro fracture surfaces that was conducted and doubled the gas production of the vertical well multiple times. However, if used the third type of drilling, directional, that is perpendicular to the hinge line and parallel to the beddings of both flanks of the anticline gas production will increase more than the horizontal drilling. The directional drilling will become perpendicular to the fracture surfaces and allow the gas and the condensate to flow into the well from all directions. Additionally, it will reduce the effect of both semi – liquid hydrocarbon condensate and vertical sediment barriers.

DEVELOPMENT OF THE WOODADA GAS FIELD

1985 ◽  
Vol 25 (1) ◽  
pp. 316
Author(s):  
C.M. Lane ◽  
R.J. Watson
Keyword(s):  
Gas Production ◽  
Commercial Production ◽  
Permeability Barrier ◽  
Production Mechanism ◽  
Well Bore ◽  
Secondary Porosity ◽  
Gas Field ◽  
The Matrix ◽  
Production History ◽  
Matrix Rock

The Woodada gas field was discovered in May 1980, when the Woodada 1 well flowed gas at a rate of seven million cubic feet per day from a carbonate unit within the Carynginia Formation of the onshore northern Perth Basin. Appraisal and development drilling has resulted in a total of 11 wells, of which seven have produced sales gas.The reservoir is estimated to have contained initially at least forty four billion cubic feet of gas-in-place in the developed part. There is a prospective area to the south with similar potential.The Woodada field is a combination structural/strati- graphic trap, where an up-dip lithology change effecting a permeability barrier seals the reservoir across a north plunging anticline. Porosity within the reservoir is secondary, with natural fractures often contributing to the production mechanism. The presence of fractures has required special attention to drilling and completion techniques. Gas production is significantly enhanced by acidization.Pressure responses measured in or between wells combined with more than two years of production history have demonstrated that there is moveable gas in the fine voids of the matrix rock, as well as in the better developed secondary porosity system. Even where there is no substantial porosity in a well bore, it has been possible to achieve commercial production rates by acid stimulation.

Intelligent Plunger Lift: Digital and Cost-Effective Solution to Unlock Gas Potential in a Large Tight Gas Field in China

2021 ◽  
Author(s):  
JingFei Tang ◽  
Beryl Audrey ◽  
Jin Lin ◽  
Xiang Zhen Meng ◽  
Chao Yu ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
Cost Effective ◽  
Gas Production ◽  
Maintenance Cost ◽  
Liquid Loading ◽  
Gas Field ◽  
Horizontal Drilling ◽  
Multistage Hydraulic Fracturing ◽  
Loading System ◽  
Data Surveillance

Abstract The field is located in a large gas producing basin in China and has prominent characteristics such as thin formation thickness, low permeability and poor reservoir connectivity. Horizontal drilling associated with multistage hydraulic fracturing has proven to be an effective technique to produce the hydrocarbon in this field. As the gas wells matures, the production rate starts to decline due to the decreasing of the bottom hole pressure which will prompt a liquid loading issue. A trending gas production loss is up to 150 mmscf in a year due to liquid loading issue alone, which is equivalent to $1.8MM revenue loss. An analytical decline rate showed that the field is declining 3.4% to 4.6% monthly due to the descending of the casing pressure, superimposed with low backflow ratio after hydraulic fracturing, which create a technical and economic challenge to produce effectively. In addition, the location between well pads are remote and far apart. This creates HSE challenge for personnel to go to the well pads, especially during icy road in the winter. Solid soap stick had been tried as a deliquifications method, unfortunately the result is unsustainable without frequent injection. It is also very much relying on human intervention. Due to that, an alternative liquid lift loading system is introduced in the field. An intelligent plunger lift has been piloted in 12 wells in the field to reduce the liquid loading issue in mid 2021. Apart from the apparent advantages of plunger lift such as mitigation of liquid fallback, zero input energy and low operating/maintenance cost, this system is not desirable to fully close well at downstroke process which comes up with increment of gas production comparing to traditional plunger lift system. One of the major advantages is the real time production data surveillance to enable remote operations based on its intelligence flow control system and downhole sensor.

Natural fractures in tight gas sandstones: a case study of the Upper Triassic Xujiahe Formation in Xinchang gas field, Western Sichuan Basin, China

2021 ◽  
pp. 1-18
Author(s):  
Yunzhao Zhang ◽  
Lianbo Zeng ◽  
Wenya Lyu ◽  
Dongsheng Sun ◽  
Shuangquan Chen ◽  
...  
Keyword(s):  
Production Capacity ◽  
Gas Production ◽  
Upper Triassic ◽  
Tight Gas ◽  
Natural Fractures ◽  
Carbon And Oxygen Isotopes ◽  
Gas Field ◽  
Xujiahe Formation ◽  
Western Sichuan ◽  
Tight Gas Reservoir

Abstract The Upper Triassic Xujiahe Formation is a typical tight gas reservoir in which natural fractures determine the migration, accumulation and production capacity of tight gas. In this study, we focused on the influences of natural fractures on the tight gas migration and production. We clarified characteristics and attributes (i.e. dips, apertures, filling degree and cross-cutting relationships) of the fractures based on image logging interpretations and core descriptions. Previous studies of electron spin resonance, carbon and oxygen isotopes, homogenization temperature of fluid inclusions analysis and basin simulation were considered. This study also analysed the fracture sequences, source of fracture fillings, diagenetic sequences and tight gas enrichment stages. We obtained insight into the relationship between fracture evolution and hydrocarbon charging, particularly the effect of the apertures and intensity of natural fractures on tight gas production. We reveal that the bedding fractures are short horizontal migration channels of tight gas. The tectonic fractures with middle, high and nearly vertical angles are beneficial to tight gas vertical migration. The apertures of fractures are controlled by the direction of maximum principal stress and fracture angle. The initial gas production of the vertical wells presents a positive correlation with the fracture abundance, and the intensity and aperture of fractures are the fundamental factors that determine the tight gas production. With these findings, this study is expected to guide the future exploration and development of tight gas with similar geological backgrounds.

Application of geostatistical seismic inversion in reservoir characterization of Sapphire gas field, offshore Nile Delta, Egypt

2019 ◽  
Vol 38 (6) ◽  
pp. 474-479
Author(s):  
Mohamed G. El-Behiry ◽  
Said M. Dahroug ◽  
Mohamed Elattar
Keyword(s):  
Reservoir Characterization ◽  
Nile Delta ◽  
Seismic Inversion ◽  
Reservoir Modeling ◽  
Connectivity Analysis ◽  
Gas Field ◽  
Geostatistical Inversion ◽  
Well Data ◽  
Reservoir Connectivity ◽  
Inversion Techniques

Seismic reservoir characterization becomes challenging when reservoir thickness goes beyond the limits of seismic resolution. Geostatistical inversion techniques are being considered to overcome the resolution limitations of conventional inversion methods and to provide an intuitive understanding of subsurface uncertainty. Geostatistical inversion was applied on a highly compartmentalized area of Sapphire gas field, offshore Nile Delta, Egypt, with the aim of understanding the distribution of thin sands and their impact on reservoir connectivity. The integration of high-resolution well data with seismic partial-angle-stack volumes into geostatistical inversion has resulted in multiple elastic property realizations at the desired resolution. The multitude of inverted elastic properties are analyzed to improve reservoir characterization and reflect the inversion nonuniqueness. These property realizations are then classified into facies probability cubes and ranked based on pay sand volumes to quantify the volumetric uncertainty in static reservoir modeling. Stochastic connectivity analysis was also applied on facies models to assess the possible connected volumes. Sand connectivity analysis showed that the connected pay sand volume derived from the posterior mean of property realizations, which is analogous to deterministic inversion, is much smaller than the volumes generated by any high-frequency realization. This observation supports the role of thin interbed reservoirs in facilitating connectivity between the main sand units.

scholarly journals Evaluation of natural gas production optimization in Kailashtila gas field in Bangladesh using decline curve analysis method

2015 ◽  
Vol 50 (1) ◽  
pp. 29-38 ◽  
Author(s):  
MS Shah ◽  
HMZ Hossain
Keyword(s):  
Production System ◽  
Gas Production ◽  
Curve Analysis ◽  
Production Optimization ◽  
Reservoir Pressure ◽  
Gas Field ◽  
Wellhead Pressure ◽  
Decline Curve Analysis ◽  
Decline Curve ◽  
Overall Performance

Decline curve analysis of well no KTL-04 from the Kailashtila gas field in northeastern Bangladesh has been examined to identify their natural gas production optimization. KTL-04 is one of the major gas producing well of Kailashtila gas field which producing 16.00 mmscfd. Conventional gas production methods depend on enormous computational efforts since production systems from reservoir to a gathering point. The overall performance of a gas production system is determined by flow rate which is involved with system or wellbore components, reservoir pressure, separator pressure and wellhead pressure. Nodal analysis technique is used to performed gas production optimization of the overall performance of the production system. F.A.S.T. Virtu Well™ analysis suggested that declining reservoir pressure 3346.8, 3299.5, 3285.6 and 3269.3 psi(a) while signifying wellhead pressure with no changing of tubing diameter and skin factor thus daily gas production capacity is optimized to 19.637, 24.198, 25.469, and 26.922 mmscfd, respectively.Bangladesh J. Sci. Ind. Res. 50(1), 29-38, 2015

Digital Workflow to Enhance Reservoir Management Strategies for A Complex Oil Field Through Real Time and Advanced Engineering Monitoring Solution

2021 ◽  
Author(s):  
Julieta Alvarez ◽  
Oswaldo Espinola ◽  
Luis Rodrigo Diaz ◽  
Lilith Cruces
Keyword(s):  
Real Time ◽  
Reservoir Characterization ◽  
Management Strategies ◽  
Reservoir Management ◽  
Gas Production ◽  
Oil Field ◽  
Oil Reservoirs ◽  
Production Operation ◽  
Digital Workflow ◽  
Operational Decisions

Abstract Increase recovery from mature oil reservoirs requires the definition of enhanced reservoir management strategies, involving the implementation of advanced methodologies and technologies in the field's operation. This paper presents a digital workflow enabling the integration of commonly isolated elements such as: gauges, flowmeters, inflow control devices; analysis methods and data, used to improve scientific understanding of subsurface flow dynamics and determine improved operational decisions that support field's reservoir management strategy. It also supports evaluation of reservoir extent, hydraulic communication, artificial lift impact in the near-wellbore zone and reservoir response to injected fluids and coning phenomenon. This latest is used as an example to demonstrate the applicability of this workflow to improve and support operational decisions, minimizing water and gas production due to coning, that usually results in increasing production operation costs and it has a direct impact decreasing reservoir energy in mature saturated oil reservoirs. This innovative workflow consists on the continuous interpretation of data from downhole gauges, referred in this paper as data-driven; as well as analytical and numerical simulation methodologies using real-time raw data as an input, referred in this paper as model-driven, not commonly used to analyze near wellbore subsurface phenomena like coning and its impact in surface operation. The resulting analyses are displayed through an extensive visualization tool that provides instant insight to reservoir characterization and productivity groups, improving well and reservoir performance prediction capabilities for complex reservoirs such as mature saturated reservoirs with an associated aquifer, where undesired water and gas production is a continuous challenge that incorporates unexpected operational expenses.

A Dynamic Workflow of Well Health Issue Prediction – Sulfur Deposition

2021 ◽  
Author(s):  
Bashirul Haq
Keyword(s):  
Material Balance ◽  
Gas Production ◽  
Health Issue ◽  
Sulfur Deposition ◽  
Gas Reservoirs ◽  
Gas Field ◽  
Actual Performance ◽  
Sulphur Deposition ◽  
Balance Analysis ◽  
Sour Gas

Abstract Sour gas reservoirs are vital sources for natural gas production. Sulphur deposition in the reservoir reduces a considerable amount of gas production due to permeability reduction. Consequently, well health monitoring and early prediction of Sulphur deposition are crucial for effective gas production from a sour gas reservoir. Dynamic gas material balance analysis is a useful technique in calculating gas initially in place utilizing the flowing wellhead or bottom hole pressures and rates during the well's lifetime. The approach did not apply to monitor a producing gas's health well and detect Sulphur deposition. This work aims to (i) modify dynamic gas material balance equation by adding the Sulphur deposition term, (ii) build a model to predict and validate the issue utilizing the modified equation. A unique form of the flowing material balance is developed by including Sulphur residue term. The curve fitting tool and modified flowing gas material balance are applied to predict well-expected behaviour. The variation between expected and actual performance indicates the health issue of a well. Initial, individual components of the model are tested. Then the model is validated with the known values. The workflow is applied to active gas field and correctly detected the health issue. The novel workflow can accurately predict Sulphur evidence. Besides,the workflow can notify the production engineers to take corrective measures about the subject. Keywords: Sulfur deposition, Dynamic gas material balance analysis, Workflow

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