Stimulation Testing

Stimulation capabilities at CSI Technologies include frac fluid design and testing, water analysis, and proppant analysis.

Test Description
rheology – model 50 HTHP rheology up to 400°F and 1,500 psi. Used for standard crosslinked gel testing (Standard ISO Testing).
HTHP rheology – model 7600 HTHP rheology up to 600°F and 40,000 psi.
Linear gel rheology Ambient pressure rheology for non-crosslinked fluids such as base linear gels. Temperature up to 190°F.
Viscosity and breaker profiles Constant shear testing performed on model 50 or model 7600 (depending on temperature and pressures desired) to determine viscosity profile or breaker effectiveness vs. time.
Simulated fracture window A large-scale physical model consisting of two pieces of Plexiglas held a 1/4 in. apart. This is used to visually observe fluid flow through a simulated 1/4-in. fracture. Useful for comparative testing between two fracture fluids. Properties such as proppant transport capabilities, for example, can be tested and qualitatively and quantitatively measured. Model is 3 ft tall and 8 ft long.
Proppant conductivity Short- and long-term proppant conductivity.
Proppant UCS Determines unconfined compressive strength (UCS) of proppant (for resin-coated proppants).
Composite sieve analysis Determines the gradation of a sample. Sieve sizes include applicable sizes through number 200 mesh.
Sphericity and roundness Characterizes the physical appearance of proppant.
Crush resistance The strength of proppant is determined by quantifying the amount of proppant crushed at a given stress.
Turbidity Determines the amount of suspended particles or fine matter present in fracture sand by measuring the optical scattering and absorption of light from particulate matter suspended in a wetting fluid.
Bulk density Describes the mass of proppant that fills a unit volume, including both proppant and porosity.
Apparent density Measured with a low-viscosity fluid that wets the proppant particle surface. It takes into account the volume of pore space inaccessible to the fluid.
Absolute density Density of the proppant, excluding the inaccessible pores in the proppant and void spaces between proppant.
Acid solubility Often used to indicate and quantify the presence of impurities in fracture sand.
Regained permeability Testing to determine the percentage of permeability reduction a fracture fluid could potentially cause as a result of fluid residual left in the formation.
Water quality testing Water testing includes chlorides, sulfates, pH, calcium, nitrates and TDS.

Fracture Fluid Design and Testing

CSI has significant experience with different types of fracture fluids. Services offered include design work and general fluid testing. Through good standing relationships with chemical providers, CSI can obtain samples and knowledge of available chemicals at a moment’s notice for baseline testing. For cross-linked gel fracture fluid systems, CSI has vast experience with designing stable systems for different temperature and application ranges. For testing of fracture fluids, CSI offers basic and advanced fluid testing, including:

  • Linear Gel rheology
  • Model 50 HTHP rheology (up to 400°F and 1,500 psi)
  • Viscosity profiles and breaker profiles
  • Model 7600 HTHP rheology (up to 600°F and 40,000 psi)
  • Viscosity profiles and breaker profiles
  • Regained permeability

CSI can also go on location and perform QA/QC testing before or during the fracture job to ensure the gel being pumped is equivalent to the design in the lab.

Model 50 HTHP Rheometer
Model 50 HTHP Rheometer
Model 7600 HTHP Rheometer
Model 7600 HTHP Rheometer

Water Analysis

The chemicals used for stimulation operations are extremely sensitive and, as such, require the base water to be at a particular quality. Furthermore, the introduction of the use of produced water as the base for the fracturing fluid has brought about entirely new product lines for stimulation chemicals. However, these new chemicals also require water at certain quality levels. CSI has full water-quality testing capabilities for both in-lab and onsite QA/QC, which includes:

  • Chlorides
  • Sulfates
  • pH
  • Calcium (hardness)
  • Nitrates
  • Total dissolved solids

Proppant Analysis

CSI has full in-lab and onsite proppant QA/QC capabilities. In-lab capabilities include all methods indicated by the proppant characterization ISO standards 13503-2 and 13503-5. This testing includes:

  • Sieve analysis
  • Sphericity and roundness
  • Crush resistance
  • Turbidity
  • Bulk, apparent and absolute density
  • Acid solubility
  • Proppant UCS
  • Short- and long-term proppant conductivity
  • Simulated fracture window