Multiphase Flowmeters in Well Testing Applications

Abstract

Abstract Dual-energy spectral gamma ray / Venturi multiphase flowmeters present an efficient and cost-effective means of testing wells in many field applications. A simple, efficient and quick procedure optimizes the utilization of these types of multiphase flow meters for well testing. This paper presents the field operating procedures for installing and using multiphase flowmeter and gives practical recommendations for performing well tests with or without a reference, such as a separator. The analysis of 415 multiphase well tests performed worldwide has provided some insights into the accuracy achieved in the field and has led to some recommendations for the test design. The ability of a multiphase flowmeter to perform a measurement in the absence of a flowing reference is essential to well testing in most applications. Furthermore, the high mobility of the equipment (with up to three wells tested in three different locations per day) allows a very efficient and short turn around time for installation and operation. The parameters required to perform the setup of a meter fall into two categories: meter static empty pipe reference and fluid properties. A detailed review of each parameter is presented along with its sensitivities when determining the flow rates of oil, gas and water. A description of the field procedure used to determine each setup parameter is provided and a series of field examples are presented that illustrate the efficiency of using multiphase flowmeters for well testing. Introduction The use of multiphase flowmeters in well testing is not new. Early developments (in the 1980s) of multiphase flowmeters have been geared towards the testing of wells mostly in the United States. In the early 1990s, the engineering of multiphase flowmeters took a form more oriented towards pure instrumentation and metering applications, with many operating companies metering departments and research centers working in close collaboration with various suppliers to advance the technologies.1–18 Key technology breakthroughs, mostly in the determination of fractions combined with a better understanding of multiphase flow dynamics, have improved the overall confidence in the techniques and led several operators to implement field applications of multiphase flowmeters. Most of the meters deployed in the oil field to date are installed permanently in production systems. Such applications will not be discussed here. We will focus on the challenges of mobile well testing operations, supplied as a full service package by a service company. Review of benefits of multiphase flowmeters Traditionally well testing is performed using single-phase flowmeters installed on the oil, gas and water outlet of test separators. Large pressure vessels, important hydrocarbon inventory in piping and separator bodies, heavy lift, large rig-up and operating crews have been some of the chores attached to well testing. Refs. 16 and 19 illustrated the benefits of multiphase flowmeters over test separators in some field applications. Although some tradeoffs are inevitable, overall multiphase flowmeters bring an efficient solution to well testing measurements. Their main benefits are gains inSafetyLogisticsDuration of the operationData quality