Multiphase Flow Meter Choke for Low-Flow Composition Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multiphase flow meters (MPFMs) face accuracy issues due to varying flow rates in oil and gas wells, particularly in unconventional wells where production declines rapidly, leading to reduced differential pressure and impaired compositional measurements.
Innovation Solution
Incorporating a choke with a choke ratio of no more than 0.4 into the MPFM's Venturi throat to reduce the cross-sectional area, combined with a broad-spectrum energy source emitting high-energy and low-energy photons, to maintain accurate phase fraction measurements across a wide range of flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If the flow rate decreases as a well matures, then the operational lifetime of the MPFM is extended, but the measurement precision deteriorates due to reduced differential pressure
Solution Approach 1:
The patent changes the physical parameters of the sampling section by introducing a choke that reduces the cross-sectional area. This increases the differential pressure across the sampling section at low flow rates, thereby maintaining measurement precision while allowing the well to operate through its natural production decline curve.
Solution Approach 2:
The patent applies local quality by creating a restricted zone (choke) within the sampling section. This localized modification affects only the pressure distribution in the sampling area, increasing differential pressure where needed without affecting the overall flow system or requiring replacement of the entire MPFM.
2Measurement precision
If a choke is introduced to increase differential pressure at low flow rates, then measurement precision is maintained, but photon absorption increases reducing measurement accuracy
Solution Approach 1:
The choke wall is designed with non-uniform thickness, having greater thickness at the edges and lesser thickness at the center. This creates different radiotransparency properties in different regions of the choke, allowing photons to pass through the thinner center region with less absorption while the thicker edges still provide sufficient pressure restriction.
Solution Approach 2:
The choke is constructed from composite materials with different radiotransparency characteristics. The material selection and configuration create a balance between mechanical strength/pressure restriction capability and radiotransparency, allowing the choke to fulfill both its flow control function and its requirement to minimize photon absorption.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution extends the operational lifetime of MPFMs by ensuring accurate measurements even at low flow rates, such as less than 50 barrels per day, by minimizing photon absorption and maintaining a suitable sampling path length.
Implementation Method 1
emitting at least high-energy photons and very low-energy photons from an energy source through a center portion of the choke, wherein at least a portion of the high-energy photons and very low-energy photons pass through choke material in a sampling direction; and detecting the portion of the high-energy photons and very low-energy photons after passing through the choke at a detector
Data Source
AI summary
A device may include a choke body having a first longitudinal end and a second longitudinal end with a choke volume therein from the first longitudinal end to the second longitudinal end, the choke volume having a center cross-sectional area of a center portion that is no more than a first end cross-sectional area. A device may include a wall of the choke body that continuous in a circumferential direction and having a first radiotransparency at a first end portion and having a second radiotransparency less than the first radiotransparency in the center portion proximate to the center cross-sectional area.