Shear History Simulator Provides Valuable Analysis of Water Based Oil and Gas Fracturing Fluids

The rheology of fracturing fluids used by the oil and gas industry is affected by a range of factors and conditions. Recently developed shear history simulators have proven especially useful laboratory tools for determining how well these fluids perform in transporting proppants.

Chandler Engineering (USA), specialists in oil well cementing, viscosity, reservoir analysis and high-pressure high-temperature instruments, has developed a Shear History Simulator (SHS) system that greatly simplifies the process of preparing and loading water-based fracturing fluids dynamically into rotational viscometers for testing.

The Chandler Model 5600 Shear History Simulator consists of a pressurised fluid reservoir, two injection pumps and three capillaries. Fluid is pumped through the capillaries at various rates and durations to simulate pumping conditions experienced during fracture simulation treatments. Each capillary is 120-feet long with a 0.085 inch internal diameter. A valve panel with a graphical representation of flow paths allows users to configure the instrument to simulate a broad range of well conditions.

The process begins with a gel-based fluid that is placed into a pressurised supply reservoir that delivers fluid to an injection pump. The system is equipped with easy connecting couplings and flexible hoses. Pressure is applied to the reservoir using a panel-mounted air regulator.

A high-pressure, corrosion-resistant, stainless steel triplex injection pump driven by a gear motor and controlled by a frequency drive controller delivers 0 to 100 ml/min of fluid, while a second stainless steel pump delivers 0-9.99 ml/min of crosslinker additive. An optional sample vessel is available for use with particle-laden crosslinker additives. The two fluids are combined in a micro-volume mixing tee, which flows directly into a multi-element kinetic mixer for thorough homogenisation.

The combined fluids then travel through the series of capillaries. Using selector valves on the front panel, the flow path can be configured between one, two or three capillary sections. Pressure transducers located at the entrance and exit of each capillary accurately monitor fluid pressures between capillaries. Digital indicators display each pressure on the front panel.

The Chandler SHS system can be operated manually as a stand-alone unit or run using Chandler’s SHS software, which monitors and records all measured parameters such as pump rate and pressure. It also displays the time required to load the proper sample volume into the cup.

Chandler Engineering focuses on serving the upstream oil and gas markets in exploration and production. Its products are used for oil well cementing, viscosity measurement, reservoir analysis and other applications such as pipeline transmission. Chandler Engineering is part of the AMETEK Oil & Gas Business Unit. AMETEK, Inc. is a leading global manufacturer of electronic instruments and electromechanical devices with annual sales of $3.0 billion.