Array laterolog and dual laterolog resistivity measurements in horizontal wells: A comparative model study

The variable mass flow in perforated horizontal wells is very complex. One reason is that the perforation can increase the roughness of the pipe wall which will increase the frictional pressure drop. The other is the fluid boundary layer and velocity profile of axial flow will be changed due to the “mixing” of the inflow with the axial flow. The influences of the perforation parameters and flux rate on the pressure drawdown in horizontal wellbore are investigated. The perforation parameters include perforation phasing, perforation diameter, and perforation density. According to the experiment results, some modes such as friction factor calculation model (the accuracy of the model is 4%), “mixing” pressure drop calculation model (the accuracy of the model is 3%), and total pressure drop calculation model (the accuracy of the model is 2%) are developed.

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Sensitivity analysis for the appraisal of hydrofractures in horizontal wells with borehole resistivity measurements

Geophysics ◽

10.1190/geo2013-0014.1 ◽

2013 ◽

Vol 78 (4) ◽

pp. D209-D222 ◽

Cited By ~ 32

Author(s):

David Pardo ◽

Carlos Torres-Verdín

Keyword(s):

High Frequency ◽

Horizontal Well ◽

Low Frequency ◽

Horizontal Wells ◽

Hydraulic Fractures ◽

Electrically Conductive ◽

Resistivity Measurements ◽

Electromagnetic Measurements ◽

Open Hole ◽

Thin Disks

We numerically evaluate the possibility of using borehole electromagnetic measurements to diagnose and quantify hydraulic fractures that have been artificially generated in a horizontal well. Hydrofractures are modeled as thin disks perpendicular to the well and filled with either sand-based or electrically conductive proppant. The study focuses on the effect of thickness and length (radius) of hydrofractures to assess their effects on specific configurations of borehole-resistivity instruments. Numerical results indicate that several measurements (e.g., those obtained with low- and high-frequency solenoids) could be used to assess the thickness of a fracture. However, only low-frequency measurements performed with electrodes and large-spacing between transmitter and receivers (18 m) exhibit the necessary sensitivity to reliably and accurately estimate the length of long hydrofractures (up to 150 m) in open-hole wells. In the case of steel-cased wells, the casing acts as a long electrode, whereby conventional low-frequency short-spaced, through-casing measurements are suitable for the accurate diagnosis of long hydrofractures (up to 150 m in length).

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