Integrated field operation and optimization

Abstract

Integrated modeling and optimization is an important method in the petroleum industry, particularly for field development and continuous asset-management evaluation. Traditional modeling consists of the application of many independent models describing the various elements of a petroleum asset in a silo-model approach, such as reservoir models, well models, surface process models, export and sales models and economic models. The effort to integrate these models such that the overall system performance can be optimized presents many technological challenges.A common field asset is modeled with emphasis on: (1) Three different reservoirs (two gas condensate reservoirs and one miscible oil reservoir), (2) A surface facility model (focusing on water handling, NGL extraction, sales-gas spec, and gas reinjection), and (3) Economic model. The surface process model interacts with the three reservoir models through distribution of available produced gas for reinjection into the three reservoirs. The multi-field asset model is introduced as a benchmark case.A decision support tool is used to develop the model and provides long-term production forecasts of gas, oil, and NGL revenue. Cost functions are introduced for all major control variables (number of wells, surface facility selection and operating conditions, and injection gas composition). Net present value is used as the target objective function.This paper evaluates optimal production strategies using several key control variables and field operational constraints. Optimization performance is tested with a non-derivative optimization solver, a constrained implementation of Nelder–Mead Simplex Reflection method. The benchmark is provided to the industry through a website containing application data files, network infrastructure, and results from our integrated optimization model.