Baski Inc. has developed the Zone Flow Tester (ZFT™) for the area of permeability testing. In this type of testing, straddle packers seal off the zone of interest and fluids are injected or withdrawn, while pressure/flow data are recorded. Click on the image below to see the construction of a ZFT™.  Conceptually, the ZFT is a straddle packer arrangement with a specialized valve instead of a slotted pipe between the packers. The ZFT accommodates three transducers that sense pressure 1) below the packer, 2) in the zone between the packers, and 3) above the zone. It also incorporates a pump shroud to house a sample or submersible pump for taking samples or performing pumping tests. Uphole equipment that supports the ZFT™ includes a riser pipe, transducer, pump cable/tubes, datalogger, flow delivery panel for injection, and discharge flow meter for pumping tests. Of course, there are also generators, inflation gas supplies, and other support equipment. A summary of the major equipment associated with the ZFT is listed below: including  information about  packer equipment, borehole equipment and surface equipment. [Back To Top]

PACKER  EQUIPMENT Packers Isolate the zone of interest by straddling it with two packers, which are either the Baski medium-duty, sliding-end packers or the ReFlexTM fixed-end packers (unconfined burst rating of 500 psi). This pressure rating is needed at the depths encountered in normal projects to reduce the chance of failure by extrusion or blowout. Access Port Valve Controls the testing fluids for injection, slug and pumping tests. The Access Port Valve (APVTM) is a pneumatically operated valve that has pipe fittings at both ends, and replaces the standard slotted pipe used between straddle packers. It is excellent for pressure build-up data without casing storage effects, and a series of APV's allows multi-level investigations. Bottom Adapter Seals the transducer transfer tube into the bottom zone and protects the porous tube end of the bottom transfer tube. In-line Adapter Directs leads into and out of the main drop piping. The In-Line Adapter (ILATM) is normally constructed of  aluminum, but stainless steel is available. [Back To Top]

BORE  HOLE  EQUIPMENT Centralizer Centers the packer string in the hole and is installed at 20-foot intervals. Pump Pumps water from the zone of interest and can be an electric submersible or pneumatically operated bladder or piston pump. Generally, the choice of a pump has no cost significance on the shroud.. Pump Shroud Isolates the pump from the fluid that surrounds the shroud, allowing the pumped fluids to enter from the bottom of the shroud and flow past the motor (thus cooling the motor). The pump shroud also seals transducer leads & pneumatic tubing through the shroud and is the strength member that supports the packers. Porous Tube End Allows the transfer tube to be filled with water, and keeps the water from draining during the short trip to the borehole static water level. It results in a more accurate reading of formation pressures without the "offset" occurring in air-filled transfer tubes. The use of transfer tubes also allows the transducers to be located near the top of the packer string, avoiding the lacing of transducer cables through the string. Transducer Carrier Protects the transducers on their trip downhole. Typically, the carrier allows the leads to run outside the drop pipe, so that the transducer is adjacent to the drop pipe, eliminating the lacing of long lengths of transducer cable through fittings into sealed chambers and through packers. [Back To Top]

SURFACE  EQUIPMENT Banding Tool Secures the transducer cables, inflation tubing, and APV tubing (collectively called leads) to the packer string. Fittings Connect all of the necessary equipment and can be provided in National Pipe Taper (NPT), American Petroleum Institute (API), and British Standard Taper (BST) thread patterns. They also include inflation equipment that consists mainly of brass tubing and stainless steel connectors. Inflation and APV Lines Connect the packer string to the necessary gas or liquid sources. Inflation tubing and APV actuation tubing is 3/16" O.D. or 1/4" O.D. nylon tubing with a burst rating to 2,500 psi (170 bar). The typical working pressure of 625 psi (43 bar) provides a 4:1 safety factor. Baski Inc. stocks 5,000 ft. reels of the nylon tubing, as well as 5,000 ft. lengths of 1/4" O.D. stainless steel tubing [316L, 0.035" wall thickness, tested to 10,000 psi (690 bar)]. Hydraulic hose rated from 3,000 psi (206 bar) to 10,000 psi (690 bar) working pressures is also available. Regulator Manifold Regulates the nitrogen pressure for inflating packers. The manifold includes a nitrogen regulator (for connection to N2 bottles) connected to a pressure gauge (1/2%) and delivers pressures up to 2000 psi. Rotameter Panel for Injection Testing Allows water flow deliveries of 0.2 ml/min to 8 l/min with a maximum pressure of 100 psi. Up to five rotameters and valving are mounted onto stainless steel panels to provide the range of flows. A water supply is necessary that is typically a 100 to 1,000 gallon water tank with pressure relief, valving for fill, delivery, and drain, and 20 feet of hose to the rotameter panel. [Back To Top]