<< Click to Display Table of Contents >> Navigation: Hydrogeologist workbench (ANSQUICK) > ANSQUICK >Lugeon (packer) tests 
ANSDIMAT offers interpretation of packer tests by the Lugeon method, where hydraulic conductivity is calculated from pressure and injection rate measurements.
The dialog window "Lugeon tests" is opened by selecting menu "File > Hydrogeologist workbench > Lugeon test".
Example of dialog window "Lacker test"  data analysis for test stages
Example of dialog window "Lugeon test"  data analysis for inection rate vs pressure plots
Before the start of a test, the maximum testing pressure Pmax is determined based on the depth of the borehole screen.
The testing process aims at sustaining a constant pressure by injecting water volumes and measuring both, pressure and water flow. The standard procedure for packer testing is explained below:
1.Pressure is changed by steps from the lowest to highest pressure as: 0.5Pmax, 0.75Pmax, Pmax, 0.75Pmax, 0.5Pmax.
2.Constant pressure P is maintained for 10 minutes at each step.
3.The water injection rate Q, required to sustain pressure, is measured every minute.
4.The Lugeon value (Lu) is calculated for each step by the formula:
where Q – average injection rate for sustaining constant pressure, l/min, lw – length of testing interval, m; P – constant pressure at each step, Pa. P0 = 1 MPа – scaling pressure coefficient.
5.Lugeon values are plotted as a bar diagram for each pressure step. Depending on the shape of the plot, hydrodynamic conditions during the test fall into one of the five categories: 1) laminar flow; 2) turbulent flow; 3) opening of fractures; 4) washing out fine material; and 5) filling in voids/fractures.
6.Water injection rates are plotted against pressure values. Depending on the shape of the plot, hydrodynamic conditions during the test fall into one of the five categories: 1) laminar flow; 2) turbulent flow; 3) opening of fractures; 4) washing out fine material; and 5) filling in voids/fractures.
Arrows show the directions of pressure changes from step to step.
7.For each step, the hydraulic conductivity is calculated using one of the three methods below:
– Moye formula:
– Thiem formula:
where ΔP – borehole pressure change , Pa; g – gravity acceleration value, m/s2; ρ – density of injected water, kg/m3.
– Lugeon formula:
1 Lu ≈ 1.3∙107 m/s ≈ 0.011 m/d.
Fracturing can be qualitatively described based on mean lugeon and hydraulic conductivity values.
Explanatory table
Field on the window top 
Title (description) of packer tests 

Table on the left 
The table contains factual measurements of pressure and injection rate for each step of the test First column  N of step Second column  The constant pressure, that is maintained during the corresponding step. Units of measurements can be selected from the dropdown menu "Pressure" The next columns contain injection rates or volume of water injected during the corresponding stage at different time intervals. The number of columns depends on the number of measurements (time intervals). The user can choose between entering flux or volume by checking one of the "Flow meter type" items. For the "Volume" option, the first measurement (Column "Start") corresponds to the measured volume before the start of the test, and the next columns corresponds to volume measurements after 1 min, 2 min etc. For the "Flux" option, the columns correspond to the injection rate measured after 1 min, 2 min etc. The last column automatically calculates the average injection rate over the entire step length. Measurement units for flux or volume can me selected from the relevant dropdown menus. 

Button "Copy" 
Copies table data on the Clipboard 

Button "Paste" 
Pastes data from the Clipboard into the table starting from the cursor location 

Table on the right 
The table contains hydraulic conductivity values (left column) and lugeon values (right column) 

Dropdown menu above the table 
Selection of calculation formula for hydraulic conductivity. ANSDIMAT uses the Moye, Thiem and Lugeon methods for calculations. After the method is changed from the dropdown menu, hydraulic conductivity values are recalculated automatically 

Button "Copy" 
Copies table data on the Clipboard 

Fields "Average value (k, Lu)" 
Calculation of average values of hydraulic conductivity (m/day) and lugeon parameter (Lu). The parameters are calculated based on the values from the table on the right 

Frame "Settings" 
Selection of number of steps, number of measurements and units of measurements 

Field "Number of steps" 
Quantity of steps with constant pressure: between 5 and 99 

Field "Number of measurements" 
Quantity of measurements of injection rate/volume in one step: between 3 and 99 

Choice options "Flow meter type" 
Selects whether flux or volume of injected water were measured for inputs on the table on the left 

Option "Volume" 
Volume of injected water recorded during the test 

Option "Flux" 
Flux (injection rate) of water recorded during the test 

Text box "Radius of influence" 
Assumed radius of influence for the test. An option is offered to assign test interval as radius of influence. When this option is not selected (the relevant box is unchecked), the radius of influence is entered manually 

Field "Density" 
Density of injected water. This field is used for converting injection rate in l/min units and for calculations of hydraulic conductivity 

Field "g, m/c2" 
Gravity acceleration coefficient = 9.8 m/s2. This value is used for converting pressure in hydraulic head in calculations of hydraulic conductivity 

List "Units" 
Dropdown menus allows selection of measurement units for pressure, flux and volume of injected water 

List "Pressure" 
Selection of pressure measurement units 

List "Flux" 
Selection of flux measurement units 

List "Volume" 
Selection of volume measurement units 

Frame "Parameters of well" 
Borehole radius and test interval 

Field "Well radius" 
Enters the radius of the tested borehole (m) 

Field "Test interval length" 
Enters tested interval (m) 

Frame "Plot" 
Choice of plots for visual analysis of hydrodynamic conditions during the test 

Option "Step  Lugeon" 
Diagram of lugeon values for the test steps (2nd column of the right table). This plot is used to characterize the test conditions (i.e. laminar or turbulent flow) 

Option "Flow  Pressure" 
Plot of stepaveraged injection rate (last column of the left table) vs pressure of injected water (2nd column of the left table). This plot is used to characterize the test conditions (i.e. laminar or turbulent flow) 

Option "Step  Pressure" 
Diagram of pressure variations for the test steps (2nd column of the left table) 

Option "Step  Average Flow" 
Diagram of average flow variations for the test steps (last column of the left table) 

Option "Volume  Time" or "Flux  Time" 
Hydrograph of flow rate or injected water volume during each the test. A type of plot depends on whether options "Flux"or "Volume"are selected. Step can be selected from the dropdown list. 

Dropdown list 
Selection of test step for plotting Flux/Volume hydrograph 

Button "Save" 
Saves lugeon test data from the current dialog window in an internal ANSDIMAT format (file with extension ATL) 

Button "Load" 
Loads file with saved lugeon test data (file with extension ATL) 