Exploring New Concepts in Subsea Field Architecture

Abstract

The present paper will explore an alternative subsea system configuration where it is possible to install dedicated equipment for each well (or group of wells) depending on its particular needs (e.g. boosting, separation, metering). This could allow achieving efficient and optimal management of the integrated system over the entire life of the field. Additionally, it opens for opportunities to optimize the operation of equipment and the utilization of resources. To test the concept, a field life study was performed on a conventional subsea oil field using a commercial software for modeling of production systems. The reservoirs were represented using a material balance model, and well rates are calculated considering the pressure drop and pressure increase (boosting) along the production system. Three cases were simulated and compared in terms of their cumulative oil production and power consumption when subsea processing is required. Case 1) standard configuration of pipeline-riser system without subsea processing unit, case 2) including a single subsea booster in the original network system, and case 3) including a modular assembly with boosting capabilities to individual wells. From all the evaluated cases, Case 3 showed the highest cumulative oil production at the end of field life. Two production strategies were tested for case 3: System demand (boosting units starting up at different times according to wells requirement) and simultaneous running mode (all boosting units starting up simultaneously). The different production strategies influence the potential for system improvement in terms of the process efficiency, production rate, and power demand.

Evolutionary Algorithm to Support Field Architecture Scenario Screening Automation and Optimization Using Decentralized Subsea Processing Modules

“…Furthermore, the standard ISO 15663 [36] recommends using the NPV as a method for ranking the options evaluated for a given project and defining the costs driver associated with each option. Therefore, the fitness function is calculated using Equation (1).…”

“…A preliminary study of the subsea gate box was performed in [1]. For this first stage of the study, the authors used a simplified version of a subsea gate box that only considered modular multiphase pumps.…”

“…For such cases, the full performance of the field is compromised by any change in the operating conditions of a given region or wells within the production network. A different approach is being proposed by [1,2], where a well or a region with a large heterogeneous performance is decoupled from the main network by installing decentralized subsea processing modules in the field architecture. This approach, called the Subsea Gate Box (SGB) [3], is addressed to increase production management flexibility by expanding the possible production strategies, considering both production constraints and reservoir dynamics, and increasing the energy efficiency to improve resource utilization.…”

Combining system-theoretic process analysis and availability assessment: A subsea case study

“…In this section, the proposed approach is applied on a novel design concept of subsea architecture named Subsea Gate Box (SGB) that arises in the Subsea Production and Processing SUBPRO 37 research center. The detailed introduction to this design concept can be found in the study of Diaz et al 38 Some simplifications are made on the original design concept for illustrative purpose. The modeling and simulation of SPN is completed by the software GRaphical Interface for reliability Forecasting (GRIF) 39 with the simulation engine Moca-RP.…”

“…The detailed introduction to this design concept can be found in the study of Diaz et al 38 Some simplifications are made on the original design concept for illustrative purpose. The modeling and simulation of SPN is completed by the software GRaphical Interface for reliability Forecasting (GRIF) 39 with the simulation engine Moca-RP.…”