The goal of this project is to extend the use of Multi-Dimensional Electrical Capacitance Volume Tomography (MD-ECVT) sensors for subsea oil and gas multiphase flow measurement to reduce subsea facility complexity, advance real-time remote monitoring of well fluids, and enable greater tieback to the surface production facility. This multiphase flow meter (MPFM) will also be tested in a relevant subsea environmental chamber to prove the mechanical integrity of the equipment in such an environment. Additionally, a datasheet will be developed for the MPFM that is representative of field operating conditions and that offers a competitive advantage over existing MPFMs on the market for subsea applications.

Tech4Imaging — Columbus, OH 43220
The Ohio State University — Columbus, OH 43220
Accuflow — Bakersfield, CA 93313
 

Current state of the art multiphase flow meter (MPFM) measurement for subsea has many drawbacks including high complexity, large size, low accuracy and low consistency across many flow regimes and operating conditions, safety risks with radiation, and high cost (sometimes in excess of $1M for a single unit).

In contrast, the current state of the art for ECVT technology depicts an accelerated acceptance by the multi-phase flow community. ECVT’s favorable features include its safety, fast imaging and measurement speeds, scalability to industrial size and conditions of pressure and temperature, flexibility for imaging complex geometries, low acquisition costs (projected $200–250k instead of $750–1,000k) and low operational cost. Additionally, ECVT sensors can be adapted to work in a wide array of industrial settings. Another application involved measuring mass flow rate and fluid dynamics of brine in a geothermal well with temperatures up to 250°C and pressures up to 300 psi. Furthermore, high-pressure flows are no longer an obstacle as ECVT sensors have been tested on a flow loop with over 5,000 psi pressure. 

The single deployable commercial product produced will be an integrable part in reducing cost, increasing efficiency, and improving safety in Enhanced Oil Recovery (EOR) systems in subsea oil fields. Successful completion of this project would provide a cost-effective solution to EOR developers for deploying multiphase flow meters (MPFM) in remote subsea oil fields. MPFMs are critical sensors for determining when to transition to EOR, knowing what method of EOR to employ, monitoring efficiency of an existing EOR method, detecting water breakthrough, monitoring well aging, monitoring separator efficiency, and custody transfer.
The new measurement techniques used in developing the flow meter under investigation will also enrich the multi-phase flow scientific literature through published articles.

• Flow Loop/Algorithm
  • The 3-phase flow loop has been designed and built at the Tech4Imaging facility.
  • In depth testing of two and three phase flows has been under way since the end of Nov 2020 which shows close validation of simulation results for three phase measurements for water dispersed flows. Largely, the data is very consistent and accurate. However, occasional inconsistencies have led us to spend time to isolate to causes of the outliers.
  • Simulation has been performed that shows accuracy is not affected when the system is calibrated and used at different, constant salinities.
  • Simulation for water continuous flows shows good accuracy of water phase measurement. However, oil and air phase measurement in water continuous flows is not consistent with the current method. We are investigating ways to improve the results for water continuous three phase measurements.
  • Simulation capability was transferred from The Ohio State University to Tech4Imaging offices to increase efficiency and bridge the gap between theory and application.
• Sensor/Subsea Chamber
  • First sensor design has been fabricated.
  • The sensor has been tested to an internal hydrostatic pressure of 2,200 PSI at room temperature.
  • The subsea environmental test chamber has been fabricated and assembled successfully.
  • The sensor assembly was placed inside the subsea chamber and pressurized from the outside hydrostatically to 3,000 PSI to simulate the subsea environment of 5,000 feet below sea level (2,248 PSI) + safety factor.
• Electronic data acquisition system
  • New components for stabilized data.
  • Temperature sensors and thermal compensation for temperature-related drift have been implemented.
  • Design for C1D1 certified housing has begun.
  • Firmware has been updated to accommodate hardware changes.
• Software
  • An embedded system has been developed to interface with the DAS.
  • Communication includes Modbus and current loop.
  • Temperature compensation is performed in the embedded system.
• Field Testing
  • A field-testing plan is being developed with our commercial partner, Accuflow, to identify a test and schedule as well as testing configuration details.

1. Investigating outliers in water dispersed three phase experimental data.
2. Investigating methods to improve three phase measurements in water continuous flows in simulation.
3. Finalizing the implementation of the temperature compensation algorithm for the DAS and Sensor to increase accuracy and repeatability.
4. Field Testing delayed due to improvements currently being made to the sensor and electronics.
5. Setting up experiment to measure the effects of changing salinity on the measurement.
6. Assembling and testing new board designs as they arrive.

New boards have been designed to achieve higher Dynamic Range and Signal to Noise ratio. This, and the addition of temperature compensation allowing the project researchers to distinguish the minute changes more accurately in signal as the volume fraction of mixture components change. These boards are currently on order and are being assembled and tested as they arrive. Initial tests look good, with boards performing as expected. In the near future, a Data Acquisition System or DAS will be assembled from the new board designs, temperature compensated, and installed on the 3-phase flow loop. Then we will begin flow testing again. It is anticipated that the improved signal stability and resolution will allow us to better interpret the test data and finalize the 3-phase volume fraction algorithm. 
In parallel with these efforts, experiments are being set up to measure the effect of salinity and temperature on the sensor response. This will allow the project researchers to predict the behavior of these sensors more accurately in the field. 
 

$ 2,997,736.00

$ 2,423,913.00

David Cercone (david.cercone@netl.doe.gov or 412-386-6571)
Tech4Imaging LLC- PI: Qussai Marashdeh (marashdeh@tech4imaging.com or 614-214-2655) 

Final Technical Report – April 2024