Showing posts with label fracing. Show all posts
Showing posts with label fracing. Show all posts

Flow Measurement for Hydraulic Fracturing and the Production of Shale Gas

Figure 1. Illustration of the fracing (fracking) process.
(Image courtesy of EPA.gov)
A “conventional” gas reservoir is produced from sands and carbonates (such as limestone). In the conventional reservoir, the gas is in interconnected pore spaces, much like a kitchen sponge, that allow easier flow to a well.  In an "unconventional" gas reservoir, such as shale, the reservoir must be mechanically “stimulated” to create additional permeability and free the gas for collection.  Permeability refers to the capacity of a porous, sediment, soil – or rock in this case – to transmit a fluid. Unconventional reservoirs include tight gas (low-porosity sandstones and carbonate reservoirs) and coal bed methane (CBM – gas produced from coal seams).

For shale gas, hydraulic fracturing (known as "fracing" or "fracking") of a reservoir is the preferred stimulation method (figure 1). This typically involves injecting pressurized fluids to stimulate or fracture shale formations and release the natural gas. Sand pumped in with the fluids (often water) helps to keep the fractures open. The type, composition and volume of fluids used depend largely on the geologic structure, formation pressure and the specific geologic formation and target for a well. If water is used as the pressurized fluid, as much as 20 percent can return to the surface via the well (known as flow back). This water can be treated and reused – in fact, reuse of flow back fluids for subsequent hydraulic fracture treatments can significantly reduce the volume of wastewater generated by hydraulic fracturing. 

The hydraulic fracturing process was used in conventional limestone and sandstone reservoirs for decades before the onset of the shale revolution. But it was not until the 1970s that significant attempts to apply the technology to gas shale were made, pioneered by DOE research and demonstration project cost-sharing with industry in such ventures as the Eastern Gas Shales Project (1976-92).

Another major technology often employed in producing natural gas from shale is horizontal drilling. The shallow section of shale wells are drilled vertically (much like a traditional conventional gas well). Just above the target depth – the place where the shale gas formation exists – the well deviates and becomes horizontal. At this location, horizontal wells can be oriented in a direction that maximizes the number of natural fractures intersected in the shale. These fractures can provide additional pathways for the gas that is locked away in the shale, once the hydraulic fracturing operation takes place.

Accurate flow measurement is important in fracking applications and required for reliable data reporting to supervisory agencies. The preferred technology for measuring flow in fracking applications are magnetic flowmeters (magmeters), primarily for their non-obstructive flow path, accuracy and reasonable cost. There are caveats associated with applying magmeters in fracking applications and selection of specialized flow meter components is required. Fracking sand is very erosive and chemicals mixed with the fracking water can be erosive. Any flow meter used in fracking applications must be rugged enough to withstand these harsh conditions. 

Flow meter designed for fracking
applications (as well as for other
abrasive slurries) by TECO.
An excellent solution that provides all the the virtues of magnetic flowmeters and overcomes performance and longevity issues referred to as "severe service flowmeters" or "slurry flow meters" designed with components matched specifically to withstand the mechanical and chemical abuse they will see. Their modifications include: 
  • A ceramic sleeved liner made of magnesia partially stabilized zirconia. This ceramic can handle the abrasion and chemical attack with very little degradation.
  • Highly polished, ultra-smooth Tungsten electrodes. The Tungsten provides outstanding wear resistance while the high-polish reduces electrical noise introduced in the electrode circuitry.
  • Special coatings, or paints, to provide exterior protection.
For more information on fracking (or fracing) magnetic flow meters, contact Thompson Equipment Company (TECO) by calling 800-528-8997 or visit https://teco-inc.com.


Source: How is Shale Gas Produced? https://www.energy.gov/fe/shale-gas-101

New Batch of Severe Service Magmeters for Fracing Service from TECO


A good customer with a global presence in the oil and gas industry just purchased a batch of specially designed TECO Severe Service Magmeters.  The customer is a "pressure pumper" with a unique Frack Blender configuration. TECO designed these mag meters with grooved end fittings to meet their requirement. The ultimate destination for these magmeters is Saudi Arabia.

For more information about severe service magnetic flowmeters, contact Thompson Equipment Company by calling 800-528-8997 or visit https://teco-inc.com.

Hydraulic Fracturing Terms and Definitions

Hydraulic Fracturing Terms and DefinitionsHydraulic fracturing is the process of using fluid, sand, chemicals, and gels to create or exploit small fractures in a sub-surface rock layer formations in order to stimulate production from oil and gas wells. This fracturing creates paths and reservoirs which increase the rate at which fluids can be taken from the wells. In some cases, this process can increase production by many hundreds of percent.

Below are common terms and definitions* used in the hydraulic fracturing process:
  • Additive Pumps – used to inject liquid additives; different types based on the additive type and additive rate.
  • Annulus – Area between two concentric casing strings or tubular strings.
  • Bottom Hole Treating Pressure (psi) – pressure being applied to the formation including net pressure.
  • Centrifugal Pumps – used on the low pressure equipment to mix and move fluid.
  • Clean Volume (gal or bbl) – volume of fluid pumped without proppant.
  • Dirty Volume (gal or bbl) – volume of fluid pumped with proppant.
  • Flowmeter – used to measure and transmit fluid flow rates; different types depending on application.
  • Frac Gradient (psi/ft) – pressure at which fluid will cause the formation rock to part.
  • High Pressure Pumps – Positive displacement pumps used for pumping downhole.
  • Hydraulic Horsepower (hhp) – horsepower being applied to the formation while pumping .
  • Hydrostatic Pressure (psi) – pressure the fluid column exerts on the formation.
  • Instantaneous Shut-in Pressure (psi) – a pressure used to calibrate the frac gradient.
  • Kick-outs – mechanical or electrical devices that activate at a preset pressure to disengage high pressure pumps.
  • Liquid Additive (gal/Mgal) – any liquid chemical added to the fluid system for a specific purpose
  • Max Pressure (psi) – the maximum WHTP that will be allowed.
  • Net Pressure (psi) – excess pressure over frac pressure required to extend the fracture .
  • Perf Friction Pressure (psi) – pressure drop across the perforations.
  • Pipe Friction Pressure (psi) – friction pressure of the fluid being pumped down the wellbore.
  • Pop-off – a mechanical device activates at a preset pressure to prevent damage to surface and downhole tubular.
  • Pressure Transducer – device used to measure and transmit pressure data.
  • Proppant – small diameter material used to keep the fracture open.
  • Proppant Concentration (lb/gal) – the amount of proppant added to one gal of fluid.
  • Shut-in Pressure (psi) – a pressure used to calibrate the frac gradient.
  • Solid Additive (lb/Mgal) – a solid chemical added to the fluid system for a specific purpose.
  • Treatment Rate (bpm) – the downhole rate that fluid is entering the formation pumping.
  • Wellhead Treating Pressure (psi) – the surface pressure at the wellhead during.
Thompson Equipment (TECO) manufactures highly engineered flowmeters designed for optimum performance in fracing applications. Contact TECO to discuss any severe flow measurement application.

TECO
800-528-8997

* from EPA.gov workshop titled "Fracture Design and Stimulation – Monitoring" (DC01:570405.2)

Severe Service Flowmeters by TECO

For flow measurement of extremely abrasive slurries in Mining, Dredging, Fracing, and Oil and Gas Exploration.

Capabilities include:
  • Liners: magnesia stabilized zirconia ceramic, aluminum oxide ceramic, polyurethane rubber, neoprene rubber, Linatex, Teflon (PTFE), rotationally molded Tefzel (ETFE), PFA, and others. 
  • Electrodes: SS, Hastelloy C (C-276), Hastelloy B, zirconium, titanium, platinum/iridium, solid tungsten carbide, tungsten carbide coating, etc. 
  • Exotic tube constructions available (100% titanium).
  • Specialty Coatings: epoxy paints, powder coat, custom colors, etc.
800-528-8997

World's First Magnetic Flowmeter Developed Specifically for Hydraulic Fracing

When suspended solids are mixed with a liquid (such as water), a mud-like substance referred to as a “slurry” is formed. Slurries are challenging because of their abrasive nature. Add a highly caustic or acidic condition to the slurry, and the magnetic flowmeters (Magmeters) used to measure flow become particularly susceptible to failure. In these situations off-the-shelf magnetic flowmeters won’t last, so consideration must be given to custom flowmeters built specifically to withstand the application’s unique requirements. Hydraulic fracturing (fracing) is one industry where the movement and handling of slurries is very common, and specially designed Magmeters should be used.

Thompson Equipment (TECO) is now offering their "Severe Application Meter (SAM)" (patent pending) which is specifically designed as the world's first Magmeter developed specifically for the hydraulic fracing industry. It is designed with an impact and wear resistant ceramic liner, solid tungsten carbide billet electrodes, and quick change Victaulic flanges. The SAM can also be retrofitted to the customers existing electronic secondary system, such as Rosemount, E+H, Yokagawa, etc.

For more information, contact TECO by calling (504) 833-6381 or by visiting https://www.teco-inc.com.