What is Packer test?
Packer test is done in borewells, which isolates a portion of boreholes to take samples of fluid in it and thus allows to test its.
Packer test is used to find out the hydraulic conductivity and Injection (lugeon) value which will be used as parameters which will then be used as an analysis for water seepage and estimates of injection type selection to reduce the graduation coefficient of rock-water or to increase rock shear strength.
Types of Packer test apparatus:
The packer test is carried out in open wells or through the cable drilling rods. The latter situation allows the packer equipment to be used in unstable wells where unstable rock wall conditions are likely to cause the tool to get stuck due to falling rock or sand.
The packer assemblies used in open boreholes and through wireline rods have different configurations. The two types of test apparatus are referred to as:
Single Packer tests and
Double or straddle packer tests
Injection (Lugeon) test procedure:
The entire drill handlebar and core barrel are lifted from the borehole and then measure the water level and insert the packer equipment into the drill hole again.
After the equipment is installed, then a pressurized water passing test is carried out. Leaks can be avoided by means of the constant pressure of the air in the packer to remain in the range of 70 psi. Water entering into rock formations is attempted to provide as much pressure as possible, at least greater than static water pressure.
Pressurized water flow is carried out in 5 stages, with an interval of 10 minutes. Based on the incoming water discharge and the recorded pressure, the hydraulic conductivity and Lugeon values can be calculated.
The discharge tests are carried out in soundings with fluid artisanal conditions (fluid with natural from the borewell). In these perforations, the pressure response of the natural formation is monitored after the balanced arrest is allowed to decay with respect to time. The data are plotted logarithmically and analyzed using Jacob’s standard straight-line techniques.
Shut-In Recovery Tests:
This test is done immediately after the discharge test. The accumulation of closing pressure over time is monitored and plotted against log10 (t / t ‘), where t is the time since the start of the discharge test and t’ is the time since the test was started of recovery.