Laying the Foundations of a Digital Gas Field Development in a Greenfield Cluster Using Integrated Modelling: A Case Study

2021 ◽  
Author(s):  
Rena Alia Ramdzani ◽  
Oluwole A. Talabi ◽  
Adeline Siaw Hui Chua ◽  
Edwin Lawrence

Abstract Field X located in offshore South East Asia, is a deepwater, turbidite natural gas greenfield currently being developed using a subsea tieback production system. It is part of a group of fields anticipated to be developed together as a cluster. Due to the nature of this development, several key challenges were foreseen: i) subsurface uncertainty ii) production network impact on system deliverability and flow assurance iii) efficient use of high frequency data in managing production. The objective of this study was to demonstrate a flexible and robust methodology to address these challenges by integrating multiple realizations of the reservoir model with surface network models and showing how this could be link to "live" production data in the future. This paper describes the development and deployment of the solutions to overcome those challenges. Furthermore, the paper describes the results and key observations for further recommendation in moving forward to field digitalization. The process started with a quality check of the base case dynamic reservoir model to improve performance and enable multiple realization runs in a reasonable timeframe. This was followed by sensitivity and uncertainty analysis to obtain 10 realizations of the subsurface model which were integrated with the steady-state surface network model. Optimization under uncertainty was then performed on the integrated model to evaluate three illustrative development scenarios. To demonstrate extensibility, two additional candidate reservoirs for future development were also tied in to the system and modelled as a single integrated asset model to meet the anticipated gas delivery targets. Next, the subsurface model was integrated with a multiphase transient network model to show how it can be used to evaluate the risk of hydrate formation along the pipeline during planned production start-up. As a final step, in-built application programming interface (API) in the integration software was used to perform automation, enabling the integrated model to be activated and run automatically while being updated with sample "live" production data. At the conclusion of the study, the reservoir simulation performance was improved, reducing runtime by a factor of four without significant change in base case results. The results of the coupled reservoir to steady-state network simulation and optimization showed that the network could constrain reservoir deliverability by up to 4% in all realizations due to back pressure, and the most optimum development scenario was to delay first gas production and operate with shorter duration at high separator pressure. With the additional reservoirs in the integrated model, the production plateau could be extended up to 15 years beyond the base case without exceeding the specified water handling limit. For hydrates risk analysis, the differences between hydrate formation and fluid temperature indicated there was a potential risk of hydrate formation, which could be reduced by increasing inhibitor concentration. Finally, the automation process was successfully tested with sample data to generate updated production forecast profiles as the "new" production data was fed into the database, enabling immediate analysis. This study demonstrated an approach to improve forecasting and scenario evaluation by using multiple realizations of the reservoir model coupled to a surface network. The study also demonstrated that this integrated model can be carried forward to improve management of the field in the future when combined with "live" data and automation logic to create a foundation for a digital field deployment.

2021 ◽  
Author(s):  
Kirill Bogachev ◽  
Aleksandr Zagainov ◽  
Evgeny Piskovskiy ◽  
Iuliia Moshina ◽  
Aleksei Grishin ◽  
...  

Abstract The creation and matching of an integrated field model including a model for part of a giant field, well models and surface network model is considered here. The integrated model was created using an innovative method of solving a unified system of equations that cover all the physical processes in the reservoir-well-surface network system; no integrator software was involved. The project involves a history-matched dynamic model covering part of a giant field, a surface network layout and well constructions with the subsurface equipment parameters. These data were fed to a single software product to create a digital twin which would allow simultaneous work with both the reservoir and the network. The approach enabled quick creation and matching of an integrated model with a lot of wells which can create forecasts for various operation modes and estimate the base case production for the infrastructure in place, as well as offers an option to connect new project wells to the current surface network.


2021 ◽  
Author(s):  
Sukrut Shridhar Kulkarni ◽  
Marliana Bt. Mohammad

Abstract This paper describes a suggestion to improvise an integrated gas planning process through network optimization. As a prudent operator it is imperative to formulate long-term gas supply outlook and scenarios to ensure efficient and effective resource management with due considerations of growth strategies while maximizing value for purpose of production-focused conversations, technical assessment of forthcoming developments, commercial arrangement policy and strategic expansions. Also, it necessitates to develop and implement resolution plan arising from supply planning areas i.e. shortfall mitigation, facilities ullage, constraint and complying specifications commitment. It thereby imposes to implement robust network optimization workflow in place to improvise the integrated gas management cycle to manage the current existing gas supply and to also regulate strategy in terms of line-ups, evacuation path of forthcoming fields economically. Precedingly integrated gas planning exercise was executed via stacking up list of production sources with forecasted demands. The precedent approach was emphasized purely on mathematical and statistical method of capitalizing the production profile and geographical traits of the production sources. Notwithstanding, the approach usually linked with identified challenges and pain points throughout the planning cycle. Challenges and pain points in integrated gas planning were briefly outlined to understand limitations of existing work process as well as the need of improvising the same by embedding network optimization by simulation modeling. It was observed that multiple challenges did occur during planning preparation until post planning implementation. Workflow for strategic integrated gas planning was established to include step by step process to illustrate the ideal case otherwise known as base case scenario. The work process for constructing a mathematical model for integrated gas planning was demonstrated to reflect the complexity of the process and landscape network. For each process, expectations were clarified to ensure robustness of the analysis. The limitations in the mathematical/statistical model workflow process was complimented by the enhancing method through network optimization. Network optimization was evaluated by leveraging on the development of holistic integrated modelling for current complex offshore facilities to empower and safeguard the proposed line up of new fields meeting technical allowances such as ullage, pressure balancing & supply/demand requirements, contaminant management in accordance with strategic planning & operations. Novel idea was established to create physical prototype (network model) of offshore supply network with building components such as source (fields), connectors (export pipelines and highways), sinks (multiple terminals), and pressure boosters (pump/compressor) were embedded in model for landscape along with multiple receiving end terminals. Network simulation model was also validated with Plant information PI data to yield representative results prior deployment. Situational analysis (what-if scenarios) were conducted to evaluate to root cause analysis and troubleshooting at several nodes in the network to cater for harmonic balance. Gap analysis was also executed to identify the necessary alterations to operating philosophy, partial segregation of system to cater for product demand and quality. Simulation network model was also utilized to explore different evacuation routes that could adhere to business rules/standards to optimize the work process and boost up the efficiency of current network. The above approach of improvising the integrated gas planning through network optimization truly enhance the end to end value chain by constituting result matter in validating the mathematical planning model with technical simulation to ensure robustness in management decision of certain strategies for the planning scenarios. It could also advocate the planning numbers by ensuring the do-ability and steer optimal solution for value maximization by deciphering the impediments and strengthening the analysis.


2009 ◽  
Vol 9 (4) ◽  
pp. 1125-1141 ◽  
Author(s):  
J. Chen ◽  
J. Avise ◽  
B. Lamb ◽  
E. Salathé ◽  
C. Mass ◽  
...  

Abstract. A comprehensive numerical modeling framework was developed to estimate the effects of collective global changes upon ozone pollution in the US in 2050. The framework consists of the global climate and chemistry models, PCM (Parallel Climate Model) and MOZART-2 (Model for Ozone and Related Chemical Tracers v.2), coupled with regional meteorology and chemistry models, MM5 (Mesoscale Meteorological model) and CMAQ (Community Multi-scale Air Quality model). The modeling system was applied for two 10-year simulations: 1990–1999 as a present-day base case and 2045–2054 as a future case. For the current decade, the daily maximum 8-h moving average (DM8H) ozone mixing ratio distributions for spring, summer and fall showed good agreement with observations. The future case simulation followed the Intergovernmental Panel on Climate Change (IPCC) A2 scenario together with business-as-usual US emission projections and projected alterations in land use, land cover (LULC) due to urban expansion and changes in vegetation. For these projections, US anthropogenic NOx (NO+NO2) and VOC (volatile organic carbon) emissions increased by approximately 6% and 50%, respectively, while biogenic VOC emissions decreased, in spite of warmer temperatures, due to decreases in forested lands and expansion of croplands, grasslands and urban areas. A stochastic model for wildfire emissions was applied that projected 25% higher VOC emissions in the future. For the global and US emission projection used here, regional ozone pollution becomes worse in the 2045–2054 period for all months. Annually, the mean DM8H ozone was projected to increase by 9.6 ppbv (22%). The changes were higher in the spring and winter (25%) and smaller in the summer (17%). The area affected by elevated ozone within the US continent was projected to increase; areas with levels exceeding the 75 ppbv ozone standard at least once a year increased by 38%. In addition, the length of the ozone season was projected to increase with more pollution episodes in the spring and fall. For selected urban areas, the system projected a higher number of pollution events per year and these events had more consecutive days when DM8H ozone exceed 75 ppbv.


2021 ◽  
pp. 1-23
Author(s):  
Daniel O'Reilly ◽  
Manouchehr Haghighi ◽  
Mohammad Sayyafzadeh ◽  
Matthew Flett

Summary An approach to the analysis of production data from waterflooded oil fields is proposed in this paper. The method builds on the established techniques of rate-transient analysis (RTA) and extends the analysis period to include the transient- and steady-state effects caused by a water-injection well. This includes the initial rate transient during primary production, the depletion period of boundary-dominated flow (BDF), a transient period after injection starts and diffuses across the reservoir, and the steady-state production that follows. RTA will be applied to immiscible displacement using a graph that can be used to ascertain reservoir properties and evaluate performance aspects of the waterflood. The developed solutions can also be used for accurate and rapid forecasting of all production transience and boundary-dominated behavior at all stages of field life. Rigorous solutions are derived for the transient unit mobility displacement of a reservoir fluid, and for both constant-rate-injection and constant-pressure-injection after a period of reservoir depletion. A simple treatment of two-phase flow is given to extend this to the water/oil-displacement problem. The solutions are analytical and are validated using reservoir simulation and applied to field cases. Individual wells or total fields can be studied with this technique; several examples of both will be given. Practical cases are given for use of the new theory. The equations can be applied to production-data interpretation, production forecasting, injection-water allocation, and for the diagnosis of waterflood-performanceproblems. Correction Note: The y-axis of Fig. 8d was corrected to "Dimensionless Decline Rate Integral, qDdi". No other content was changed.


2018 ◽  
Author(s):  
Robert Reinecke ◽  
Laura Foglia ◽  
Steffen Mehl ◽  
Tim Trautmann ◽  
Denise Cáceres ◽  
...  

Abstract. To quantify water flows between groundwater (GW) and surface water (SW) as well as the impact of capillary rise on evapotranspiration by global hydrological models (GHMs), it is necessary to replace the bucket-like linear GW reservoir model typical for hydrological models with a fully integrated gradient-based GW flow model. Linear reservoir models can only simulate GW discharge to SW bodies, provide no information on the location of the GW table and assume that there is no GW flow among grid cells. A gradient-based GW model simulates not only GW storage but also hydraulic head, which together with information on SW table elevation enables the quantification of water flows from GW to SW and vice versa. In addition, hydraulic heads are the basis for calculating lateral GW flow among grid cells and capillary rise. G3M is a new global gradient-based GW model with a spatial resolution of 5' that will replace the current linear GW reservoir in the 0.5° WaterGAP Global Hydrology Model (WGHM). The newly developed model framework enables in-memory coupling to WGHM while keeping overall runtime relatively low, allowing sensitivity analyses and data assimilation. This paper presents the G3M concept and specific model design decisions together with results under steady-state naturalized conditions, i.e. neglecting GW abstractions. Cell-specific conductances of river beds, which govern GW-SW interaction, were determined based on the 30'' steady-state water table computed by Fan et al. (2013). Together with an appropriate choice for the effective elevation of the SW table within each grid cell, this enables a reasonable simulation of drainage from GW to SW such that, in contrast to the GW model of de Graaf et al. (2015, 2017), no additional drainage based on externally provided values for GW storage above the floodplain is required in G3M. Comparison of simulated hydraulic heads to observations around the world shows better agreement than de Graaf et al. (2015). In addition, G3M output is compared to the output of two established macro-scale models for the Central Valley, California, and the continental United States, respectively. As expected, depth to GW table is highest in mountainous and lowest in flat regions. A first analysis of losing and gaining rivers and lakes/wetlands indicates that GW discharge to rivers is by far the dominant flow, draining diffuse GW recharge, such that lateral flows only become a large fraction of total diffuse and focused recharge in case of losing rivers and some areas with very low GW recharge. G3M does not represent losing rivers in some dry regions. This study presents the first steps towards replacing the linear GW reservoir model in a GHM while improving on recent efforts, demonstrating the feasibility of the approach and the robustness of the newly developed framework.


Author(s):  
A. V. Veretevskaya

The article deals with an acute problem of integration of Muslim immigrants and their descendants in France. The author follows the problem throughout its history and analyzes its modern status. The article provides thorough analysis of the French Integration Model. The author concludes with a prospect on its use in the future.


2021 ◽  
Vol 13 (20) ◽  
pp. 4090
Author(s):  
Amit Kumar Batar ◽  
Hideaki Shibata ◽  
Teiji Watanabe

An estimation of where forest fragmentation is likely to occur is critically important for improving the integrity of the forest landscape. We prepare a forest fragmentation susceptibility map for the first time by developing an integrated model and identify its causative factors in the forest landscape. Our proposed model is based upon the synergistic use of the earth observation data, forest fragmentation approach, patch forests, causative factors, and the weight-of-evidence (WOE) method in a Geographical Information System (GIS) platform. We evaluate the applicability of the proposed model in the Indian Himalayan region, a region of rich biodiversity and environmental significance in the Indian subcontinent. To obtain a forest fragmentation susceptibility map, we used patch forests as past evidence of completely degraded forests. Subsequently, we used these patch forests in the WOE method to assign the standardized weight value to each class of causative factors tested by the Variance Inflation Factor (VIF) method. Finally, we prepare a forest fragmentation susceptibility map and classify it into five levels: very low, low, medium, high, and very high and test its validity using 30% randomly selected patch forests. Our study reveals that around 40% of the study area is highly susceptible to forest fragmentation. This study identifies that forest fragmentation is more likely to occur if proximity to built-up areas, roads, agricultural lands, and streams is low, whereas it is less likely to occur in higher altitude zones (more than 2000 m a.s.l.). Additionally, forest fragmentation will likely occur in areas mainly facing south, east, southwest, and southeast directions and on very gentle and gentle slopes (less than 25 degrees). This study identifies Himalayan moist temperate and pine forests as being likely to be most affected by forest fragmentation in the future. The results suggest that the study area would experience more forest fragmentation in the future, meaning loss of forest landscape integrity and rich biodiversity in the Indian Himalayan region. Our integrated model achieved a prediction accuracy of 88.7%, indicating good accuracy of the model. This study will be helpful to minimize forest fragmentation and improve the integrity of the forest landscape by implementing forest restoration and reforestation schemes.


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