Using an Electromagnetic Flowmeter for the Oil and Gas Industry

A hole is prepared using drilling mud which cools the drill bit, carries the rock cuttings back to the surface and stabilizes the wall of the well bore hole. Once the hole extends below the deepest aquifer, the drill pipe is removed and replaced with steel pipe, known as the ‘surface casing’. Next, cement is pumped down through the casing and then back up between the steel pipe to form the borehole wall, where it sets. This cement bond prevents any fluids moving vertically between the casing and the hole. In doing so, it creates an impermeable barrier between the well bore and any freshwater sources. Once the drilling is done and the final casing is installed, the drilling rig is removed. Then a connection between the final casing and the rock holding the oil and gas is established. The well is now complete.

Well

Pos.	Description
1	Well head
2	Cemented steel casing to protect aquifier
3	Drinking water aquifer
4	Impervious shale layer

 

Drilling

The Challenge

Precise control of the flow rate of the drilling mud used (to cool the drill bit) and measurement of the rock cuttings carried back to the surface is crucial in preparing the well. Drilling mud going down the borehole is a mixture of water, sand and a range of chemicals which makes flow measurement difficult due to abrasion. In order to measure the drilling mud, the flowmeter has to be able to withstand abrasion of the drilling mud as well as harsh environmental conditions such as moisture, varying ambient temperature ranges and vibration in the drilling rig.

Drilling mud

The Solution

ABB’s robust ProcessMaster electromagnetic flowmeter is designed to meet rigorous oil field production requirements helping lower risk and increase process up-time. ProcessMaster provides features such as:

• Optimized, long lasting sensor lining materials to ensure resistance to chemical corrosion and abrasion resulting in longest sensor service life.
• Designed with flush mounted measuring electrodes, unlike many other flowmeter designs, ABB’s ProcessMaster sensor has no rotating parts protruding into the pipe which can wear requiring regular maintenance and negatively impact process up-time.
• Potted sensor to protect internal sensor components against moisture and vibration, helping to assure lowest maintenance.

ProcessMaster sensor

Oil / Water Separation

The Application

Once the well is completed the production begins. Natural gas and oil flows up the well bore. The water collected along with hydrocarbons during the well’s production life is referred to as “produced water”. Most of the produced water is the water that had been pumped underground to increase the flow of oil. A separator removes the water from the oil. Usually, the volume of the water is stable throughout the well’s life and a challenge for mechanical flowmeters due to abrasive solids.

Oil / water separator

Pos.	Description
A	Inlet oil / water separator
B	Outlet for water
C	Outlet for oil
D	Outlet for gas
1	Well head
2	Separator
3	Water storage
4	Oil storage

 

Separator

The Challenge

The “produced wellhead fluid” is a multi-part mixture containing gas, sand and chemicals. To maintain oil and gas production, continuous and reliable operation of the separator is essential.

ProcessMaster

Oil / water separator

Pos.	Description
1	Separator
2	ProcessMaster

 

ProcessMaster's self cleaning measuring electrodes

The Solution

Maximizing separator efficiency, ABB’s ProcessMaster meets highest levels of reliability without being affected by sand or oil in the water.

Standard ProcessMaster features include:

• Long lasting sensor lining materials to ensure resistance to abrasion resulting in longest sensor service life resulting in low maintenance costs.
• Self-cleaning, measuring electrodes reduce the impact of oil build-up.
• Approvals according to ATEX, IEC, cFM allow for installation in hazardous areas.
• A range of communication protocols enables integration into management systems to maximize asset optimization.
• On initial installation, the self-configuration sequence automatically replicates all data from the sensor into the transmitter eliminating the potential for human errors and leading to faster start-ups.
• The user-friendly interface allows quick and easy data entry for all process parameters. The “Easy Setup” menu guides the operator step-by-step through the parameterization without the need for intensive training.

Produced Water - Management

The Application

Oil production requires millions of gallons of water for a well. Water for injection has to be sourced, transported or piped to the well site. Water management plays a key role in operating a well as every drop costs money and the well has to be operated as economically as possible. Besides sourcing, transportation and storage, there are different ways to handle produced water.

Treatment and reuse on site

Produced water is treated on site and pumped back underground to maintain oil flow of the well. By reusing the water costs are lowered and it reduces the dependency on fresh water sources.

Final disposal

Produced water goes into the pit, or is stored in tanks on-site, from where it is piped or trucked to the disposal well site, stored in a tank and injected underground for permanent storage using high pressure pumps.

The Challenge

Getting the best levels of efficiency and performance from the production process requires precise measurement of the total amount of water consumed or disposed.

The Solution

ProcessMaster delivers the power to solve the most demanding flow measurement application. Proven to be consistent and accurate, ProcessMaster will reliably give you proven and repeatable measurements to account for total amount of produced water.

ProcessMaster display

Wellpad layout

Produced Water - Treatment

The Application

Produced water treatment includes oil/water separation, removal of large particles and additional filtering before being pumped into storage tanks. Further treatment is required to reduce suspended solids and dissolved solids. This results in thickened sludge which needs to be handled. Final treatment of the water uses ultrafiltration to remove dispersed hydrocarbons. Evaporation technology can potentially deliver a distillate which meets drinking water quality standards. Depending on the produced water management treatment and disposal strategy, a variety of these treatment processes are used.

The Challenge

To run this process in the most efficient and reliable way, a robust flowmeter is required to measure accurately chemicals that are used to reduce suspended solids and dissolved in the produced water.

Filtration technology requires a flowmeter capable of measuring forward flow while processing the water and reverse flow when cleaning the filters. Low conductivity could be another challenge for some electromagnetic flowmeters depending on which filtration technique is used.

The Solution

Water filtering technologies that result in either low conductivity or gas bubbles are no challenge for ProcessMaster’s advanced signal processing providing superlative measurement performance with long-term stability. Whether an integral, remote or pipe mounted installation is required, a configurable common electronics platform provides the best tailor-made solution.

The Flowmeter provides features such as:

• Smallest outer dimensions to meet the needs for integration in skids.
• Forward and reverse flow measurement is a standard.
• No additional pressure drop from parts protruding into the pipe.
• Double sealed measuring electrodes minimize the risk for leakage enhancing reliability.
• Process optimized linings and measuring electrode materials ensure resistance to chemicals.

Wellpad layout

Pos.	Description
1	Water trucked to and from the site
2	Oil / gas wellhead
3	Oil / water separation
4	Oil storage
5	Water storage
6	Wellhead for high pressure water injection
7	Produced water injected underground to boost oil production
8	Oil accumulation
9	Fresh water source

 

ProcessMaster with remote and integral mount design

Produced Water – Final Disposal / Wellhead Injection

The Application

Produced water goes into the pit or is stored in tanks on-site from where it is piped or trucked to the disposal well site, stored in a tank and injected underground for permanent storage using high-pressure pumps. Final disposal must be in accordance with environmental regulations.

The Challenge

Based on the layout of the wellhead injection, the flowmeter sensor must withstand the high pressure produced as a result of pumping produced water underground. Installed on the suction side of the pumps, the sensor has to withstand variations in pressure which could include vacuum. Space is premium as most measurement is done on a provided skid.

The Solution

ProcessMaster compact version. Sensor and transmitter are mounted as a single entity allowing for integration in skid.

The flanged sensor design covers pressure ratings as high as ANSI Class 2,500. A wafer sensor is also available up to ANSI Class 300.

For ProcessMaster, powerful doesn’t mean complicated. The intuitive design allows for easy setup, with a sensor memory simplifying installation by eliminating configuration errors. Take advantage of simple installation, commissioning, configuration and maintenance – start saving time and money from day one.

Wellhead injection

Pos.	Description
1	Produced water storage
2	Oil wellhead
3	Oil / water separation
4	Oil storage
5	Produced water storage
6	Produced water transportation
7	Final disposal

 

ProcessMaster wafer style and flange sensor

Water Transportation

The Application

Water for injection into the ground has to be sourced, transported or piped to the well site. Produced water goes into the pit or is stored in tanks on-site from where it is piped or trucked to the disposal well site.

The Challenge

With the cost of trucking water to and from a site, an extremely reliable, accurate and repeatable flow measurement device is necessary to account for the total amount of water being transported.

The Solution

ProcessMaster delivers more than reliable and accurate measurements. When integrated with an asset management solution, the instrument plays a key role in maximizing asset optimization.

Standard ProcessMaster features include:

• No rotating parts protruding into the pipe resulting in less maintenance compared to other flow metering technologies.
• The user-friendly interface allows quick and easy data entry for all process parameters. The “Easy Setup” menu guides the operator step-by-step through the parameterization without the need for intensive training.
• Robust design withstands harshest environmental conditions.

Produced watertrucked to final disposal site

ProcessMaster product offering

Fracking

The Application

When natural oil and gas is trapped in impermeable rock and cannot migrate to form a deposit, this unconventional accumulation has to be stimulated in some way before it will begin to flow. Hydraulic fracturing is a technique to stimulate the oil or gas.

A mixture of water, sand and chemicals, is pumped at high pressure into underground rock layers where the oil or gas is trapped.

This is pumped from tanks with equipment mounted on trucks or skids on the surface. The high pressure of the fluid creates small fissures in the rock. The sand holds open the fissures, allowing the oil or gas to migrate from the rock pores where it is trapped to a producing well where it can be brought to the surface at higher flow rates. The higher rate makes operation of the well more economical. The “fracturing fluid” consists of approximately 90% water, 9% sand and 1% chemicals and gelling agents.

The purpose of the gelling agent is for lubrication in order to make the fluid more viscous and better able to carry the sand. This is necessary to hold the fractures open. Further chemicals reduce friction, attack microbes and prevent equipment corrosion.

By using ABBs electromagnetic flowmeters, precise control of the fracturing fluid and the blending of the additives is achieved. Once the fracturing process is complete, the production begins. Initially fracturing fluid, and then natural gas or oil, flows up the well bore.

In the course of initial production of the well, about 25-75% of the fracturing fluid water is recovered. It is recycled back to the surface and is referred to as “flow back water”. This water may contain hydrocarbons, fracturing sand and pieces of plastic, metal or cement from drilling. As the well comes more and more online, flow-back water transitions to produced water. Produced water is collected along with hydrocarbons during the well’s production life. Usually the volume, chemistry and suspended solids are stable throughout the well’s life and no challenge for ABBs ProcessMaster range of electromagnetic flowmeters.

Component flows at hydraulic fracturing

Pos.	Description
1	Dumper truck
2	Storage tank
3	Blender truck
4	Pumper truck
5	Well and wellhead

 

Principle of hydraulic fracturing

Pos.	Description
1	Well
2	Marcellus shale
3	Fissures
4	Shale is fractured by the pressure inside the well
5	Natural gas flows from fissures into well
6	Sand keeps fissures open
7	Mixture of water, sand and chemical agents

 

The Challenge

Dilution Skid

In this skid a range of additives and acids are watered down to form the fracturing gel. Corrosion resistant wetted parts can be a challenge for flowmeters.

Acid dilution skid

Blender Truck

The blender truck continuously blends the fracturing gel with sand to form the final (downhole) fracturing gel. For optimum fracturing, precise control of the fracturing fluid and the blending of the additives is key. Abrasion is the challenge here for the flowmeter.

Chemical additive blending

Pumper Truck

The pumper truck sends the mixture of sand, water and additives down the borehole using high pressure pumps.

Blender truck

The Solution

ABB’s ProcessMaster range of electromagnetic flowmeters is the first choice for installations in fracking applications. They are the perfect fit for skid installation, require minimal upstream/downstream straight pipe runs and provide high measurement accuracy. Unlike turbine meters, electromagnetic flowmeters have no moving parts to break or wear out, that can require downtime and maintenance. They reduce or even eliminate expensive service, replacement part costs, and down time. ProcessMaster is proven to be robust and reliable. For installations on pumper trucks and for measuring acids and chemical additives, the sensor design covers pressure ratings as high as ANSI Class 2,500. Optimized linings such as rubber or ETFE ensure resistance to abrasion and chemicals. Approvals according to ATEX, IEC as well as FM and cFM allow for installation in hazardous areas.

Offshore Oil and Gas Rigs and FPSO's

The Application

A FPSO (Floating Production, Storage and Offloading) is a standalone ship-shaped structure. The wellheads or subsea risers from the sea bed are positioned on a central turret so that the ship can rotate freely to point into wind, waves or current. The processing equipment aboard the FPSO is similar to what would be found atop a production platform. Usually built in modules, FPSO production equipment can consist of water separation, gas treatment, oil processing, water injection and gas compression, among others. Hydrocarbons are then transferred to the vessel's double-hull for storage. Crude oil is off-loaded to a shuttle tanker at regular intervals. The individual steps in O&G production are similar to the ones onshore, for example drilling and wellhead injection to increase production. Also, oil-water separation and produced water treatment. In addition to the oil and gas related water treatment / management, there is potable water, chilled water and ballast water to be managed and measured. Ballast water is used to stabilize vessels and to maintain the structural integrity when not fully loaded.

Offshore oil production

Pos.	Description
1	FPSO ship
2	Tanker offloading buoy
3	Drilling platform
4	Existing well centers

 

The Challenge

In addition to the challenges onshore, offshore installations require even a more robust, corrosion resistant flow metering devices. The outer housing has to withstand the harshest environmental conditions such as a sour gas or sea water atmospheres.

The Solution

ProcessMaster entirely made from stainless steel

ABB’s robust ProcessMaster is designed to meet these challenging requirements:

• All 316 stainless steel construction for toughest operating environmental conditions.
• Fully welded sensor made from 316 stainless steel.
• Potted sensor to protect internal sensor components against moisture and vibration.
• Sensor design covers pressure ratings as high as ANSI Class 2,500.
• Optimized, long-lasting sensor lining and electrode materials to ensure resistance to chemical corrosion and abrasion resulting in longest sensor service life.
• Approvals according to ATEX, IEC, as well as FM and cFMus allowing for installation in hazardous areas.
• Marine approvals (DNV).
• Smallest outer dimensions enable installation in restricted on-board spaces. The user-friendly interface allows quick and simple data entry for all process parameters without the need for intensive training.

This information has been sourced, reviewed and adapted from materials provided by ABB Measurement & Analytics.

For more information on this source, please visit ABB Measurement & Analytics.