Method of Nondestructive Testing for Technical State of Casing Strings in Oil-and-Gas Wells Basing on the Transient Electromagnetic Method

IEEE Trans. Instrum. Meas.

Peyton

2013

The electromagnetic induction measurement of dimensions, integrity, or material properties of conductive objects is especially challenging in the case when the electrical conductivity of these objects spans five to seven orders of magnitude. Such an application is the conductivity measurement of the surrounding rocks from within a metal casing of an oil well. The rock conductivity measurement is required in order to determine and revaluate hydrocarbon-bearing layers. We present the first experimental verification of the single-well through-casing induction measurement on a scaled laboratory model of a borehole lined with a stainless steel or copper casing surrounded with a low-conductive medium. The measurements are in the frequency range of 2-16 kHz (10-80 Hz in case of the actual borehole). We explain the theoretical background of the method, describe the scaled model and experimental procedure, and discuss the experimental results. The measurement results are in agreement with the theoretical predictions (relative error less than 15%), and the equivalence of the results for the steel and copper casings (average relative discrepancy less than 10%) corroborates that the rock conductivity measurement can be corrected for variations in the casing properties (dimensions, electrical conductivity, and magnetic permeability).

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Section: Methodsmentioning

confidence: 99%

Scaled Experimental Verification of Single-Well Induction Conductivity Measurement Through Nonmagnetic Casing

IEEE Trans. Instrum. Meas.

Peyton

2013

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“…For such a measurement system, sensitivities to the casing properties depend on selection of the excitation frequency and axial separation between the transmitter coil and receiver coils [3,4]. Adequate spacing and frequency are chosen based on experimental studies or empirical relations [4][5][6]. In our previous work, we have shown that an analytical model based on the work of Dodd and Deeds could be successfully employed in prediction of the experimentally established effects of coil separation, frequency and pulsed excitation [3,7].…”

Section: Introductionmentioning

confidence: 99%

Lumped representation in inductive measurement of metal casing properties

2010 IEEE Instrumentation &Amp; Measurement Technology Conference Proceedings

2010

In low-frequency evaluation of oil-well steel casing using a transmitter coil and several receiver coils, high measurement accuracy is required to successfully resolve individual casing properties. The results of such measurements are usually only lumped parameters: casing factor and permeability-to-conductivity ratio. In this paper, we generalize the two lumped parameters into one space-frequency dependent parameter using an analytical model based on the truncatedregion method and the series expansion of the vector magnetic potential. Using the generalized lumped parameter and the sensitivity analysis, we evaluate the traditional positioning of the receiver coils and discuss the frequency dependence of the measurement uncertainty of the lumped parameters.

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“…Measurements of oil-well steel casing (tube) properties (wall thickness, inner diameter and electromagnetic properties-magnetic permeability and electrical conductivity) are important for assessment of the physical condition of the casing [1][2][3][4][5][6]. Low-frequency (10 Hz-100 kHz) electromagnetic measurements of the casing properties are based on measurements of the impedance of a single coil or the voltage induced in a pick-up coil by an exciter coil.…”

Section: Introductionmentioning

confidence: 99%

“…Low-frequency (10 Hz-100 kHz) electromagnetic measurements of the casing properties are based on measurements of the impedance of a single coil or the voltage induced in a pick-up coil by an exciter coil. Such measurement systems are centred inside the casing and usually moved along the axis to determine the physical condition over the entire casing's length [2][3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Analytical modelling in low-frequency electromagnetic measurements of steel casing properties

Šnajder

2007

NDT & E International