How does a packer test work?
This in-situ test uses bladders, or packers, to seal off the borehole section of interest. Using water, a constant pressure is then applied to the sealed borehole interval and the resulting changes in water flow rate are measured (i.e. loss of water to the formation).
How to conduct packer test?
The hydraulic testing consists of lowering a packer tool down through the drill casing and into the borehole at a specified elevation, applying a constant hydrostatic pressure measured at the ground surface, and monitoring the water flow into the formation over time.
What is Lugeon value?
More specifically, the Lugeon test is used to measure the amount of water injected into a segment of the bored hole under a steady pressure; the value (Lugeon value) is defined as the loss of water in litres per minute and per metre borehole at an over-pressure of 1 MPa.
How to test borehole pressure?
Water pressure testing in rock consists of pressurized injection of water into boreholes drilled into the rock mass and recording the measured water flow rate under the applied pressure(s). The borehole is discretized into intervals, or stages, which are isolated through the use of single or double packers.
What is permeability testing?
Permeability (hydraulic conductivity) can be determined by undertaking in-situ tests in boreholes or standpipe piezometers. The test measures the permeability (k) of the soil and because it is carried out in-situ provides a more reliable result than can be determined in the laboratory.
What is permeability test for rock?
5.2 Permeability. -The capacity of a porous or fractured rock to conduct liquid or gas (usually water); also called hydraulic conductivity. 5.3 Equivalent Permeability. -The permeability of a rock mass, assuming that the rock mass can be represented as one uniform and porous medium over the entire test interval.
What is permeability test of soil?
Permeability Test of Soil Soil permeability, in terms of a permeability coefficient (k), measures a soil’s ability to allow water to pass through it. Soils are permeable materials due to their grain structure and the existence of interconnected voids. more ยป
What is a good borehole flow rate?
In order to pump the borehole at a sustainable rate, which will also accommodate the dry seasons, it is recommended that the borehole be pumped at approximately 70% of its yield. Hence, if a borehole is producing 1000 litres per hour then we will want to abstract the borehole water at 700 litres per hour.
What is a packer permeability test and how is it used?
Packer permeability tests are used routinely in geotechnical investigations to allow estimation of hydraulic conductivity by analysis of pressure/flow rate response during controlled injection of water into a section of borehole, isolated by packers.
Can Packer testing become routine in conventional site investigation?
The paper includes a suggested specification for the testing procedure such that high-quality, reliable, useful and economic packer testing may become routine in conventional site investigation.
What is inflatable-packer leakage?
The application of inflatable-packer testing is commonly used in all sorts of geotechnical investigations. During the test, a frequently ignored problem is the unforeseen occurrence of leakage around the packers, which leads to a high risk to wellbore failure as well as equipment stuck.
What is a borehole Packer tool?
The packer tool has one or more inflatable rubber packers that are designed to develop a seal in the borehole and prevent the migration of fluid across the seal. The packer testing equipment, provided by Gregg Drilling, included a water pump, inflatable packers for HQ-size borings attached to a water pipe, a water pressure gauge, and a flow meter.