VIKIZ

Applications

Vertical wells

  • Visual express-estimation of the fluid saturation nature,
  • Distinguishing reservoirs with estimation of effective thickness,
  • Resistivity determination in the area from a well to the undisturbed part of formation,
  • Indication of a bordering zone,
  • Search for both water/oil and gas/water contacts, and transition zone also.

Wells with horizontal completion

  • Estimation of location of both the roof and bottom of a reservoir relative to a borehole,
  • Location of water/oil and gas/oil within reservoir,
  • Distinguishing subhorizontal impermeable beds,
  • Resistivity determination of both formation and shoulder beds,
  • Estimation of electrical macroanisotropy in thinly bedded reservoirs,
  • Refinement of angles between a wellbore and formation penetrated by the wellbore.

Specifications

Measurement range of resistivity, Ohm.m 1-200
Vertical resolution, m:  
while evaluating the true thickness 0.1
while interpreting 0.8
Drilling fluid minimal resistivity, Ohm.m 0.02
Wellbore diameter, m 0.12-0.3

Configuration

The VIKIZ equipment consists of the downhole and the surface tools. The first one includes the logging tool complex and electronic-measuring unit. The complex consists of five electromagnetic logging tools of different depths and the WP electrode.

Every logging tool contains one transmitting coil, and two receiver coils. The phase difference between voltages induced in the receivers. The recorded parameter is identically related to the resistivity of the rock, surrounding the well.

Electronic-measuring unit provides:

  • electromagnetic field excitation in the environment;
  • measuring coils signal conversion;
  • phase difference and WP signal measurements;
  • digital information transfer through the conventional 3-vein wireline to the surface tool or to the logging station.

Characteristics of borehole tool

Max. operating temperature, °C 120/150/175
Max. hydrostatic pressure, MPa 60/100/140
Overall dimensions:  
Diameter, m (inch) 0.073(2.87)/0.086(3.39)
Length, m (inch) 4(157.48)
Weight, kg 50/60
Working frequencies, MHz from 0.875 to 14
Zonde length, m 0.5-2
Power supply:  
Supply voltage, V 220±22
Power consumption, watt 55
Duration of uninterrupted work, hours 8
Average lifelength, hours at least 500
Average durability, years at least 5
Vibration:  
Frequency, Hz 10-70
Max. acceleration, m/s² 30
Shocks:  
Number of shocks per minute 1-50
Max. acceleration, m/s² 50
Shock duration, ms 6-12

Basic units of borehole tool

Radiotransparent shell

App2a

Zonde

App2b

Electronic part

App2c

Protective housing

App2d

Scheme of the zonde part of borehole tool

App

Surface panel of VIKIZ tool

Basic service functions are input of information from a downhole tool, its transformation to the form suitable for recording, and storage of calibrating values.
While using computer logging station, the surface device can be substituted by special program.

App2e

VIKIZ software (MFS VIKIZ 98)

Application:

Soft5
  • Interpretation of highly inclined intervals
  • Visualization and preprocessing
  • Express inversion
  • Inversion and reliability estimation
  • Visualization of results