The sand column was then saturated with deionized water by allowing upward flow to minimize air entrapment using a variable speed pump (Fluid Metering, Syosset, NY, USA) until steady-state flow condition was achieved (Fig. 2).
Open image in new window Fig. 1 Schematic of experimental apparatus for nitrogen foam injection, 1 nitrogen tank, 2 gas mass controller, 3 foam generator, 4 core holder, 5 back pressure valve, 6 hand booster pump, 7 atmospheric valve, 8 produced fluid metering system, 9 ISCO pump, 10 simulated water, 11 foaming solution, 12 oil, 13 heating oven.
The working alternative required the coupling of a mechanical pump (QV variable speed pump, Fluid metering, Inc., NY) with the illustrated custom made jet pump.
Two solvent pumps (STH0CTCLF17, Fluid Metering, Inc., NY) with a minimum dispensing volume of 2 μL were installed, each connected to a 60 mL bottle filled with a spray solvent.
The factors affecting gas production of the CBM wells are, in decreasing order, the ratio of the critical desorption pressure to the initial reservoir pressure, the volume of the fracturing fluid per meter, the gas content, the volume of the fracturing sand per meter, the thickness, the permeability and the depth.
The experimental work was performed by using a computer-controlled, dual-cell high-pressure PVT unit (made by ROP Corporation, France) equipped with video camera-monitor-recorder system and on-line Anton-Paar fluid density meter.
The former generates the seismic tremor-like noise recorded by the OBSs and the latter generates the flow transients recorded by the fluid flow meters.
We suggest that high sensitivity fluid flow meters can be utilized to detect transient tectonic strain events in offshore environments where traditional geodetic techniques lack resolution or are not possible.
It may be possible to use binary state valves in a pulse width modulation scheme to meter fluid, but this may introduce undesirable affects such as water hammer, excessive part wear and slower response.
At times it called to mind early-20th-century scores by Tansman and Villa-Lobos, but it had original touches as well, not least a fluid approach to meter (particularly in the first two movements) and lively contrapuntal give and take between the two lines.
