A Synergistic Approach to Well Performance Monitoring
Authors: Thrasher T.S. 
Published: December 2007

A synergistic approach to monitoring well performance combines separator test and meter data, collected for production allocation, sales and other reporting requirements, with reservoir, well test, production logging, geology and geoscience data to develop a more complete understanding of individual well deliverability. Combining these sources of production and reservoir data, a monitoring program can be established that provides routine evaluation of key company assets and a diagnostic tool for production improvement.

This paper discusses the integration and utilization of well performance data into routine reservoir engineering activities, as the fundamental component to a successful production performance monitoring program. Equally important is operator commitment to establish the monitoring program as an integral part of the production and reservoir management plan. A discussion of the program being implemented within Phillips Petroleum is reviewed and provided as an example.

Introduction

Phillips Petroleum has a long history of gas and oil well performance pioneers that have developed the company's culture in the area of gas well performance, well deliverability analysis, tubing design, production forecasting, and multilayer concepts and analysis methods. These technologies have been captured and supported as a core set of required skills for all reservoir and production engineers. A continuous effort has also captured these technologies as part of the Petroleum Engineering Desktop computing suite of programs. Recent enhancements of the GasWell and OilWell Analysis modules that are part of the Well Performance Model, tightly integrate the technical computing engine with field performance data. Further integration is in progress that will allow production and reservoir engineers access to electronic metering instrumentation that is becoming more prevalent in today's field automation systems. Communication networks onshore and offshore are being implemented and linked to internal networks for data transfer. The ultimate goal of the well performance monitoring system at Phillips Petroleum is to provide capture of key data elements and automated updating of production databases for engineering analysis. Description of Well Performance Monitoring Well performance monitoring is the process of routinely evaluating the well deliverability of flowing oil, gas or water injection wells based on estimated flow potential compared to actual. A proven method for this evaluation is application of the wellhead and bottom hole backpressure curve. Surface and bottom hole data are collected and used to construct a backpressure curve for each well. The engineering responsibility is to identify production potential using the backpressure curve as a diagnostic tool. Two major components affect well deliverability, operational factors and reservoir parameters.

Operational Factors Surface and bottom hole flow conditions are an important part of the governing parameters that control well production. Major flow conditions that impact production rate include sales line or compressor inlet / discharge pressure, separator pressure, bottom hole draw down pressure limitation, and gas lift or submersible pump lift pressure. Production tubing can be a limiting or restrictive component to the deliverability of a flowing oil or gas well. Surface flow parameters are normally recorded on a daily basis and are a major part of the performance database. Common parameters include choke setting, wellhead flowing or shutin temperature and pressure, fluid gravity, casing pressure, and separator or meter conditions.

Reservoir Parameters The main reservoir parameters that affect bottom hole deliverability are mobility, total completion damage (skin effect), and pressure.