Integration of Production and Process Facility Models in a Single Simulation Tool - PEMEX E&P San Manuel Asset
Authors: Morales Urosa Fernando Luis , Cruz Velazquez Juan , Garrido Hernandez Aaron M. 
Published: February 2016

Abstract
Traditionally in the upstream business, operational decisions are made separately at the reservoir, production and surface facility levels, using only their respective knowledge, experience and engineering tools without limited coordination between them, sometimes bypassing important considerations from other components of the overall production system, outside of their specific domain. For example, a common practice in the oil industry is to generate a production forecast derived from a reservoir-based model, without taking into account surface facility constraints that could lead to unrealistic approximations. Restrictions in compression power or pump capacity, for example, could impose significant limitations over the well and surface network performance that could impact long term field management plans if they are not properly identified and solved.
PEMEX E&P San Manuel complex produces in excess of 276 mmscf/d and 13,100 BOPD from 10 fields (mostly gas and condensates, but also oil fields) through 69 wells using 6 process facilities and its corresponding pipeline network. Built more than 25 years ago, this PEMEX E&P facility, originally designed for much higher gas and liquid rates than the current ones, faced several slug and counter-pressure problems arising from over- and under-capacity of in its current surface infrastructure. This work describes how a team of reservoir, production and process engineers, developed and implemented a data, simulation and analysis workflow to identify the well-network-process system's major bottle necks and made recommendations of several low cost optimization alternatives to overcome them. The project's results of implemented recommendations increased production in excess of 2,000 BOPD, with no additional investment, and reduced the asset's operational cost by more than USD$ 600,000 USD a year. This simulation tool also proved to be very valuable for early identification of well optimization opportunities, strategic planning and informed decision making, considering the size of the full well-surface facility system.

Summary
Efficient optimization of large and complex production facilities (involving wells, pipeline networks, process facilities etc.) requires a joint effort of several domain engineers, who, generally, work in different engineering departments of the operating company (reservoir, production, operations and surface facilities). However, the analysis and decisions made by those departments are generally made independently rather than using a common approach. Thus, most of the decisions have a limited influence on the overall performance of the system. In recent years, operating oil and gas companies have started to address this problem and have started to organize multifunctional teams to better analyze their assets to improve operations and optimize production. However, proper workflows and technology must be set in place to allow different domain engineers share ideas properly and lead into proper integrated analysis.
The following sections of the work describes, phase by phase, how a team of Schlumberger and PEMEX specialists with reservoir, production and process engineering expertise, developed and implemented a workflow to put together a single integrated well-network-process simulation model, and used it to identify and implement several cost effective production optimization opportunities of San Manuel Production System.

Project Scope
In August 2006, Schlumberger-Mexico was contracted to develop an integrated study of San Manuel's production facility (PEMEX's Muspac Asset). The project covered the analysis of the production system from the bottom hole of all currently active wells (69 in total) through pipeline networks and process facilities (separation, compression, etc.) to the point of sale, in order to identify the system's major bottlenecks and make recommendations to overcome them and, if possible, reduce the facility's operational cost. The Schlumberger/PEMEX team undertook this joint 'Asset Management' project deploying an innovative software solution to examining the performance of an entire asset.