Use of a sampling apparatus for calibrating electronic mass/flow fraction meters in a pipeline

• US 5,894,080 A
• Filed: 12/23/1996
• Issued: 04/13/1999
• Est. Priority Date: 06/29/1994
• Status: Expired due to Term

• Current Assignee: Petrotech ASA (Umbrellastream LP, Inc.)
• Original Assignee: Bj.O Slashed.Rn Dybdahl
• Inventors: Dybdahl, Bj.o slashed.rn
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): FAYYAZ, NASHMIYA SAQIB
• Application Number:
  US08/765,129
• Time in Patent Office: 841 Days
• Field of Search: 73/1.02, 73/1.06, 73/1.25, 73/863.81, 73/863.82, 73/863.85, 73/863.86, 73/863.83, 73/1.16-1.36
• US Class Current: 73/1.25
• CPC Class Codes: E21B 49/086 Withdrawing samples at the surface
• CPC Class Codes: G01N 1/2035 by deviating part of a fluid stream, e.g. by drawing-off or tapping
• CPC Class Codes: G01N 2001/105 from high-pressure reactors or lines

Abstract

In order to eliminate heavy and expensive test separators on board offshore platforms, the invention proposes to use a sampling apparatus, which is designed, shaped and adapted to take fluid samples isokinetically from a mass flow containing a two or multi-phase fluid flowing in a pipeline. The pipeline is assigned calibratable electronic mass flow/fraction meters, the task thereof being to determine the produced amounts/share of the respective fractions (oil, gas, water/condensate, formation sand, etc.), and deliver data for such a determination to a computer. The sampling apparatus is coupled to the pipeline at a through-going hole for insertion/withdrawal of a probe having at least one orifice plate and being included in the sampling apparatus, as well as being adapted to be placed across substantially the complete internal diameter thereof and, following conclusion of sampling, to be withdrawn from the pipeline. Upon the withdrawal of the probe, the pipeline'"'"'s insertion/withdrawal hole for the probe becomes closed by means of a check valve which, possibly may be included in the sampling apparatus. Fluid samples taken isokenitically by the sampling apparatus are analyzed in order to determine corresponding fraction values. The values determined from the corresponding fraction values can be used as prescribed (reference) values as a base for any necessary calibration of the electronic fractions meters.

Claims

1. A method of isokenitically sampling fluid flowing within a pipe and calibrating mass flow/fraction meters comprising the steps of:

opening a check valve disposed adjacent to a through hole;

inserting an isokenitic sampling probe through the through hole, said probe having at least one orifice plate;

taking a sample of fluid within the pipe with the probe;

withdrawing the probe from the check valve and the through hole;

closing the check valve;

analyzing the sample; and

calibrating a mass flow/fraction meter attached to the pipe based on results of the sample analysis.

2. The method of claim 1 further comprising the step of mixing the fluid within the pipe upstream of the through hole.

3. The method of claim 2 further comprising the steps of:

inserting a mixing body into the pipe a suitable distance upstream of the through hole before the probe is sampling the fluid; and

removing the mixing body from the pipe.