Hydraulic fracturing experiments in transparent materials.

Hydraulic fracturing: facilities and capabilities

CSIRO has world-class laboratories and equipment to conduct experimental and theoretical research on hydraulic fracturing.

  • 8 June 2010 | Updated 14 October 2011

CSIRO conducts laboratory-scale to large field-scale experimental investigations ranging from fundamental mechanics studies to development of novel field applications of hydraulic fracturing for mining, geothermal and carbon sequestration applications.

Our research laboratory is based in Clayton, Victoria, and our field equipment is mobilised from our development facility to sites around Australia and overseas.

Expertise

Our team is comprised of geological, civil, and mechanical engineers, applied mathematicians, and mechanical and instrumentation technical staff.

CSIRO has extensive expertise in hydraulic fracturing techniques.

As a group we have expertise in:

  • hydraulic fracturing mechanics
  • non-destructive testing
  • inverse problems
  • finite element and boundary element modelling
  • asymptotic analysis
  • fracture mechanics
  • geology.

Additionally, we have extensive experience in equipment and instrumentation design and manufacturing.

Facilities and capabilities

Our facilities are equipped with specialised instrumentation and equipment to develop and provide innovative technical capabilities closely aligned with industry needs.

  • Laboratory

Our laboratory, where we perform hydraulic fracturing experiments, centres around a polyaxial loading frame and positive displacement pump.

We can provide up to 25 MPa confinement individually on three-axes to specimens up to 400 mm on a side. The pump allows us to precisely inject fluids at high pressure.

We are able to measure the full-field opening and crack front location for hydraulic fractures growing in transparent materials, such as Perspex and glass.

Our laboratory centres around a polyaxial loading frame and positive displacement pump.

This photometric method enables viewing while confinement is applied to the specimen, the equipment required includes:

  • two video cameras
  • a light source built into a loading platen
  • a top plate with a viewing window on the polyaxial loading frame.

Using these transparent materials has allowed us to study the mechanics of hydraulic fracture growth in detail while mimicking in situ stress.

For non-transparent specimens, such as rocks, we track hydraulic fracture growth using an ultrasound monitoring system that consists of up to 32 single-ended or 16 pairs of transducers.

  • Field equipment

We have an extensive set of field fracturing equipment ranging from large 700 horsepower (hp) fracturing pumps to small 10 hp testing pumps. 

The hydraulic fracturing pumps can be used to create fractures using water, linear gel or cross-linked gel with or without plastic coloured proppant to mark the fracture path.

The fracturing pumps cover a range of injection rates from less than 5 litres per minute up to 1 500 litres per minute and pressures of up to 140 MPa.

We have injection rods that allow deployment of open-hole inflatable packers to 1 000 m depth.

We typically work in HQ-size (96 mm diameter) or NQ-size (76 mm diameter) boreholes.

Tests that we can carry out include:

  • Our facilities are equipped with specialised instrumentation and equipment to develop and provide innovative technical capabilities closely aligned with industry needs.
    injection/falloff well tests

  • fracture breakdown or step-rate tests with or without abrasive jet notching of the borehole

  • fracture height growth studies in openhole with acoustic scanning of the borehole before and after fracturing.

  • preconditioning trials to determine fracturing pressure, orientation and growth rate 

  • inducing caving in mining (either in metalliferous or coal mines)

  • sand propped stimulation trials of in-seam gas drainage holes in coal

  • enhancing rock mass permeability for CO2 sequestration or in situ leaching

  • fundamental studies of fracture growth at full scale in mine back or highly instrumented environments.

The equipment is modular which allows it to be deployed at small sites on the surface or in underground mine tunnels. Special purpose equipment or instrumentation is often developed for particular applications.

  • Field monitoring

We have a surface tiltmeter array (using the Applied Geomechanics Inc Lily tiltmeter) that is used to monitor fractures as they are placed into the rock mass to depths of 1 000 m.

Analysis of the tilt data, using new efficient methods developed by CSIRO, determines the hydraulic fracture orientation (strike and dip) and volume.

Piezometers and extensometers are deployed around field sites to provide fracture pressure and opening data remote from the injection borehole.

  • Numerical modelling

We develop and continuously enhance our analytical and numerical models that are applied to analyse theoretical and experimental results.

Our two-dimensional (2D) hydraulic fracturing model includes full coupling of viscous fluid flow and fracture opening.

We develop and continuously enhance our analytical and numerical models that are applied to analyse theoretical and experimental results.

This model takes into account fluid lag, frictional interfaces (fractures or material property boundaries), and can be applied to bi-material and tri-material problems and half- and full-space problems.

A borehole modelling capability has been recently added, allowing analysis of fracturing initiation and re-orientation problems.

We have a pseudo three-dimensional (3D) commercial fracture design model (Simfrac from Taurus Reservoir Solutions Ltd in Calgary) that includes the standard features and has been enhanced to include:

  • pressure-dependent (or nonlinear) leakoff
  • interaction with a free surface
  • and equivalent modulus and multiple parallel fracture effects.

Find out more about CSIRO Earth Science and Resource Engineering.

Publications

Zhang X, Jeffrey RG, Thiercelin M. 2009. Mechanics of fluid-driven fracture growth in naturally fractured reservoirs with simple network geometries. Journal of Geophysical Research – Solid Earth, in press.

Jeffrey RG, Bunger AP, Lecampion B, Zhang X, Chen ZR, van As A, Allison DP, De Beer W, Dudley JW, Siebrits E, Thiercelin M, Mainguy M. 2009. Measuring hydraulic fracture growth in naturally fractured rock. Paper SPE 124919. In: Proceedings of the SPE Annual Tech. Conf. and Exhibition. New Orleans, Los Angeles. October 4-7.

Rohde AH, Bunger AP. 2009. Fluid flow visualisation for hydraulic fracture experiments. In: Proceedings of the Second Thailand Rock Mechanics Symposium. Chonburi, Thailand. March 12-13, 2009.

Jeffrey RG, Zhang X, Thiercelin M. 2009. Hydraulic fracture offsetting in naturally fractured reservoirs: Quantifying a long-recognized process. Paper SPE 119361. In: Proceedings of the SPE Hydraulic Fracturing Technology Conference. The Woodlands, Texas. January 19-21.

Bunger AP. 2006. A photometry method for measuring the opening of fluid-filled fractures. Measurement Science and Technology. 17: 3237-3244.