Oilfields produce flows as a mixture of oil, water and gas. Measuring these components has long been an expensive and tricky business. Now, ABB has collaborated with Arundo Analytics to create a cloud-based virtual multiphase flowmeter that derives measurements from existing data and devices.
Espen Storkaas ABB Offshore Oil & Gas, Digital ABB, Oslo, Norway, espen.storkaas@no.abb.com; Mogens Mathiesen Arundo Analytics, Oslo, Norway
The popular image of an oil strike where a fountain of oil shoots into the sky is a rather outdated and misleading one. Such productive, easily accessible oil fields have, as far as is known, all been discovered and tapped long ago. Modern oil and gas production is more discreet and is often played out in remote or underwater locations. And to have a stream of oil as pure as the cascade shooting from the derrick in those old images is a rare occurrence. In reality, flows from an oil reservoir contain a forever-changing mix of oil, gas, water and sand →1.
As an oilwell ages, the proportion of produced water (the so-called watercut) increases – some wells operate with watercuts of over 95 percent.
Though sandscreens near the production zone catch much of the sand, some can remain in the flow – an undesirable situation as flowing sand has a very heavy erosive effect on pipelines, valves etc. If gas is present in small, noncommercial quantities it is flared off; higher gas content is put into a production stream.
Traditional multiphase flow measurement
Measurement of the various components of this multiphase flow is clearly of interest to oilfield operators. Indeed, multiphase flow measurement in the oil and gas industry has a long history and many different approaches have been tried over the decades, each with its advantages and disadvantages.
Gravity separators have been a popular approach. These allow the various components to separate out into individual layers and be piped away. However, separators have latency issues and have to be very bulky and heavy if high flows are involved – not an ideal situation when real estate on an offshore platform or other location is both expensive and hard to come by.
Partial separators cost less, are smaller and can be transported more easily but provide only a snapshot of the multiphase flow.
Multiphase flowmeters have also proven popular in recent decades →2. These meters exploit a variety of principles and physical parameters – such as temperature, pressure, density, ultrasonics, electromagnetics – to calculate each component of the flow. This richness of sensing principles and associated hardware and software comes at a cost: the meters are complex to produce and calibrate, and many experienced multiphase meter engineers are reaching retirement age. Though smaller and less costly than separators, multiphase flowmeters are still expensive to buy, install and operate. Also, as no two oil and gas applications are the same, off-the-shelf flowmeters are not a viable option and meters have to be custom-built to specific requirements. Oilfield operators are, therefore, choosy about where these meters are used. Now, however, digital technology is completely changing the world of multiphase metering, allowing operators of all sizes to profit from multiphase metering that is low-cost and scalable, and that requires no additional field hardware.
From physical to virtual multiphase measurement
Arundo Analytics and ABB have collaborated to create the first cloud-based virtual multiphase flowmeters for the offshore oil and gas industry. The new solution will be part of the fully integrated ABB AbilityTM portfolio.
The experience of Arundo Analytics complements that of ABB: Arundo Analytics provides cloud-based and edge-enabled software for the deployment and management of enterprise-scale industrial data science solutions. Their software exploits machine learning and other analytical methods to connect industrial data to advanced models, the insights from which allow better decision making. ABB, on the other hand, has more than 50 years of experience with modeling and simulation – including modeling of individual phases and mixed fluids in multiphase streams – that provides analytical insights for the oil and gas industry.
The new cloud-to-cloud ABB Ability Virtual Multiphase flowmeter connects ABB Ability and Arundo’s Composer and Fabric software and makes multiphase metering much more affordable for oil and gas operators. The analytics provided by the virtual flowmeter give operators real-time data on the constituent properties of any given stream of produced fluids →3.
Nothing extra needed
A major feature of the new product is that is uses existing information about the field as well as data from the standard instrumentation already fitted on the well and pipeline system. From these data sources, real-time individual flow rates for oil, gas and water are calculated. This means that the Virtual Multiphase flowmeter does not particularly need physical multiphase meters or any special hardware – it simply uses the devices, such as pressure, temperature and flow sensors, that are already there. Any qualified device from any manufacturer can be used.
The financial implications of this aspect are hard to overstate: By using what is already there, users can save hundreds of thousands of dollars that would otherwise be spent on the purchase, set-up and support of multiphase measurement equipment such as separators or flowmeters. Furthermore, the need to find specialists skilled in installation, commissioning and calibration of separators or flowmeters is eliminated.
Further savings are made by avoiding a well shutdown. The ABB Virtual Multiphase flowmeter is completely non-interventionary so wells do not have to be taken out of production to allow a physical flow measurement and the potential revenue loss from thousands of barrels of nonproduced oil is averted.
Cloud-to-cloud
The tool uses a three-phase flow model based on specific well data that includes:
• Information on well geometry and profile, eg length, inclination, diameter, etc.
• Pressure, volume and temperature data.
• Wellhead choke characteristics.
• Fluid compositions from lab tests.
• A minimum of three months’ operational data.
Real-time data collected from field instruments is used to update the model and continuously improve its interpretative power.
Both ABB Ability and the Arundo Analytics software are cloud-based. This makes it easy not only to share data between these two platforms but also to share data with any relevant and authorized parts of the client organization. A dashboard is provided to allow access to any of the Virtual Multiphase flowmeter data stored in a customer’s data repository.
The scalable nature of the tool means that organizations that have previously been unable to continuously measure their multiphase flows can now do so at a fraction of the cost that would previously have been incurred to put the necessary infrastructure in place. If operations expand or more extensive monitoring is needed, the scalable pay-as-you-grow model makes it simple to add capability. And once an organization has subscribed to the tool, it can be made universally available, enabling it to be used worldwide to monitor and compare the performance of multiple wells.
Multiphase and beyond
With viable, accessible oil and gas reserves becoming harder and more expensive to find and exploit, the need to optimize the efficiency and productivity of existing assets is paramount. By providing analytics as a service, the Virtual Multiphase flowmeter gives companies real-time data on the constituent properties of any given stream of produced fluids and, thus, more transparency into their operations so they can find cost-efficient, reliable solutions and minimize operational costs. Operators of all sizes can profit from this economic and scalable solution.
By using Arundo software to combine physical models with the latest in IT and machine learning, ABB can build on the experience gained from the Virtual Multiphase flowmeter development to deliver additional innovative cloud-based, data-driven applications to the oil and gas industry.
