Economic Benefits From Automated Optimization of High Pressure Gas Usage in an Oil Production System

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractAn integrated solution was required to optimise the use of gas in a complex network installed for gas lifting operations, gas export and reservoir re-injection. The solution was required because the compression facilities represent a major element of the cost of operating the field and therefore it is important that the high pressure gas is used as efficiently as possible. It is also important that recommendations from the optimiser are implemented with minimal delay and therefore closed-loop optimisation was selected, which requires that the optimiser is integrated with the field's SCADA system.The complexity of the system to be optimised presented a unique challenge. Traditional nodal analysis modelling techniques are generally not robust when applied to complex, non-hierarchical networks. Consequently, the Sequential Linear Programming (SLP) optimisation technique is applied to solve the computer model of the low pressure gas gathering system, multi-stage compression facilities and high pressure gas distribution system. The novel implementation of this technique simultaneously simulates and optimises since it is able to select the best combination of pressures and flowrates from the set of all combinations which will satisfy the problem constraints.This paper describes the development of the optimisation application, the network and well models and the underlying mathematical techniques. The integration with SCADA and other databases is described, along with a discussion of how the form of the integration reflects the desired workflow for operating and optimising the field. Finally, the paper provides a quantitative assessment of the benefits realised by applying the optimisation application in the field. These benefits are obtained through increased oil production, reduced compressor fuel gas consumption and reduced venting of low pressure gas.

A review of closed-loop reservoir management

“…Results showed that the optimal design was a large slug injection of low concentration surfactant and polymer, followed by a small slug of subsequent polymer injection. One of the best examples about gas lift optimization has been achieved by McKie et al (2001), in which gas lift injection rates, compressor settings, and field fuel consumption for more than 500 wells were optimized to maximize liquid production. Codas et al (2012) integrate simplified well deliverability models, vertical lift performance relations, and flowing pressure behavior of the surface gathering system to develop a framework of integrated production optimization for complex oil fields.…”

Stability analysis of network-based cooperative resource allocation strategies

“…On the other hand, in [26] it has been proposed to apply adaptive resource management techniques based on feedback control theory to resource allocation problems that arise during run-time adaptation using PID controllers. In [27], a sequential linear programming algorithm is used to optimize a complex oil production system by selecting the best combination of pressures and flow rates of the set formed by the gathering station, compression plants, and high-pressure gas manifolds.…”

Genetic Algorithms and Ant Colony Approach for Gas-lift Allocation Optimization

“…It is common to neglect this mization approaches 1),6), 24) . Various optimization techeffect if the network is small or the pipelines are not so niques are examined in the literature; both derivativelong as to induce a considerable pressure drop to the based such as sequential linear programming (SLP) 18) network. In this case each well can be considered to sequential quadratic programming (SQP) 22) and general-, be non-affected by other wells in a production network ized reduced gradient (GRG) 25), 26) and stochastic methods and the GLPCs can be plotted individually.…”