L52322 Effects of Methanol on Gas Measurement
Upstream natural gas and related fluid operations often require the injection of methanol to prevent flow line constrictions and blockages caused by water and natural gas hydrates. Both the constrictions and methanol have a significant impact on measurement accuracy. Natural gas chromatographic analysis and related measurement practices do not account for constrictions or methanol in natural gas streams. API 14.2, A.G.A. Report No.8, A.G.A. Report No.10, ISO 12213, ISO 20765 and GPA 2172 do not account for methanol. Measurement and operation practices rely on accurate information to reduce errors. This report analyzes the effect of methanol on gas measurement physical properties. It establishes the relative effect of methanol on the physical properties by applying the Gas Research Institutes high accuracy equation of state for natural gases as distributed by API, A.G.A, ISO and others as API MPMS Chapter 14.2, A.G.A. Report No.8, A.G.A. Report No.10, ISO 12213 Part 2, and ISO 20765. It applies GPA 2172 for the analysis of the sensitivity of the heating value to methanol.
L52361 Smart USM Diagnostics - Phase I
It has long been known that all ultrasonic flow meters, especially those that exploit multiple paths to achieve higher accuracies are capable of extensive self-diagnosis. However, each manufacturer of the technology has tended to develop diagnostic tools specific to each particular device. This has led to a confusing mix of offerings that are not transportable between meters, and whose interpretations are not always consistent.
PR-015-06601-R01 Evaluation of Clamp-On Ultrasonic Meters as Field-Portable Diagnostic Tools
Author(s): George, Delgado
This study has continued work begun in 2005 to evaluate the use of commercially-available clamp-on ultrasonic meters (USMs) in diagnosing natural gas flow conditions that can produce measurement errors in traditional natural gas meters. In this project, a prototype multi-array clamp-on USM and a commercially available two-path clamp-on USM were mounted on a conventional orifice meter run with a 19-tube bundle flow straighter subjected to well-conditioned flow and a series of adverse flow conditions. Measurements from the clamp-on meters were compared to measurements from the orifice meter under adverse conditions. The objectives of the study were to determine the ability of the clamp-on meters to diagnose abnormal flow conditions that can produce measurement errors in conventional orifice meter configurations, identify the flow profiles within the meter run, and quantify the orifice meter measurement error.
PR-343-06605-R01 Analysis of Recalibration Data in the Public Domain
Author(s): Letton-Hall Group
Public domain information on USM recalibration was reviewed. Additional publications have addressed the stability of USMs that are permanently installed in the flow calibration loops at Certified Flow Calibration facilities.