We conducted a theoretical study to investigate the techniques for developing a geologically complex turbidite reservoir in highly constrained oil field underlying a city. Not only does the geology present significant challenge in terms of heterogeneity and anisotropy, the surface constraints make it very difficult to plan the development of wells because of health, safety, and environment (HSE) issues. With a strong economic focus, the study incorporated various sensitivities and uncertainties in CAPEX and OPEX in establishing novel ways of optimizing infill well locations, drilling in an urban area, and enhancing hydrocarbon production through reservoir simulation practices. For reservoir simulation, well logs, production history, and laboratory data were taken from an analogous field. This, plus the presence of certain unique events in the history of some of the wells, imposed limits on the study. The methodology of the dynamic modelling is unconventional in terms of analyzing the field for forecasting right after initialization, followed by a detailed history match considering the numerous complexities of a turbidite environment. This allows greater time for field development planning, which is typically given the least attention in modelling because of time constraints. The prediction comprises three cases—a no-further-action case, an infill drilling case, and a waterflood scenario. A combination of vertical and horizontal well trajectories was used to achieve the best output across a range of economic sensitivities over multiple scenarios. The study covered a broad range of realizations of well trajectories, well placement, optimized drilling, and production services, such as is done in a constrained urban environment like Los Angeles, California. Our modelled city was Houston, Texas, a well-known urban environment. As a result of the modelling, a technique was developed to account for environmentally safe development within this example. The technological and economic conclusions make this a foundation study for profitable development of reservoirs underneath a populated area. The study may also be instrumental in exploitation of turbidite reservoirs, which present challenges in current North Sea and Brazil offshore development and in recently discovered submarine fans in the Gulf of Mexico deep marine environment.

CNV field in offshore Vietnam is experiencing excessive surface back pressure due to extended production pipeline and increasing field gas-oil ratio (GOR), which not only constraints the production from existing wells but also creates a challenge in evaluating production gain from future development activities. Therefore, it is critical to properly account the back pressure effect to generate a reliable long term production forecast for further investment decision. This paper describes the details of integrating subsurface dynamic reservoir simulation model with surface network simulation model to holistically assess the impact of back pressure. The conventional method of using standalone dynamic simulation model is compared against the integrated model. The well control mode in the reservoir model is updated with the response of the network model, which consist of wells, topside piping, facility equipment and export pipelines. With this approach, the surface pressure constraints and responses will be captured, and the reservoir, well and network performance will be impacted accordingly. A unified field management is designed using an advanced orchestration engine to control the well operating conditions, schedule well activities and activation of equipment in the operational cycle. Thorough assessment can be performed with the inclusion of accounting interactions between reservoir and network parameters. This integrated modelling workflow allows multiple domains of reservoir engineering, production engineering and engineering contractors to collaborate and achieve a better understanding of the impact of surface back pressure by producing a representative forecast of production profile. To address the back pressure problem in the current facility, debottleneck the surface network and improve production was evaluated by installation of additional surface equipments such as booster pump and compressor. In general, the integrated model provides critical insights to the field development planning, evaluation for de-bottle necking surface system and production optimization. There is lack of publication on the successful usage of the integrated surface network with subsurface dynamic simulation as it is uncommon for this feature in conventional modelling workflows. This paper describes the successful case of the implementation of an integrated simulation modelling workflow to simulate long term surface back pressure effect, back pressure from additional production into the system, and benefits of new surface equipment installation. Highly efficient and accurate prediction tool was developed in the scope of this study.

This theoretical study about the development of a turbidite reservoir is unique because it considers the combination of the surface and the health, safety, and environment (HSE) constraints of the urban overlying the reservoir. Although geology poses deep challenges in terms of reservoir heterogeneity, anisotropy, compartmentalization, and pressure drives, the attempt to develop oil fields in an urban environment makes it very difficult to plan facilities, transport, services, and operations because of HSE issues. This study is a continuation of a previous study in which the background, modeling, and economic analysis of the earlier study is combined with stronger HSE concepts to make the study more holistic. With a strong focus on health and environment, this paper establishes guidelines for managing the risks of urban development. Reservoir management is guided by sensitivities and uncertainties on CAPEX and OPEX, establishing novel ways of optimizing infill well locations, drilling practices in a city, and enhancing hydrocarbon production through reservoir simulation practices. The geological, geophysical, and engineering data for the study are generated to represent analogous turbidite reservoirs whereas the HSE well planning recommendations are derived from urban oilfield developments in Los Angeles and Long Beach, California. The methodology of dynamic modeling is nonconventional in terms of analyzing the field for forecasting immediately after initialization followed by a detailed history match considering the numerous hurdles of turbidite environment. This allows greater time for field development planning, which is conventionally given the least attention because of time constraints. Therefore, the prediction comprises a no-further-action case, an infill wells case, and waterflood scenarios, with a combination of vertical and horizontal well trajectories exhibiting the best output in a span of vast economic sensitivities over multiple scenarios. The most noticeable part of the study is the wide range of realizations on well trajectories, well placement, optimizing drilling, and production services. Our modeled city was Houston, Texas, a well-known urban environment. As a result of the modeling, a technique was developed to guide for environmentally safe development within this example. The technological and economic conclusions make this a foundation study for profitable development of reservoirs underneath a populated area. The study may also be instrumental in exploitation of turbidite reservoirs, which present challenges in current North Sea and Brazil offshore development and in recently discovered submarine fans in the Gulf of Mexico deep marine environment.