Abstract
A petroleum well for producing petroleum products that incorporates a system adapted to controllably measure a formation resistivity using induction chokes to form electrically isolated piping structure sections that can be used as the formation contact electrodes for time-varying current, and methods of producing petroleum products while measuring formation resistivity, are provided by the present invention. The system comprises a fIrst induction choke, a second induction choke, and a device. TheIfirst induction choke is located about a piping structure of the well. The secondinduction choke is also located about the piping structure of the well, but the first induction choke is distally spaced from the second induction choke. The device is located outside of the piping structure and comprises two terminals. A first of theterminals extending from the device is electrically connected to the piping structure on I one side of the fIrst induction choke. A second of the terminals extending from the ,.device is electrically connected to the piping structure on another side of the first induction choke, between the first and second induction chokes, such that the downhole device is electrically connected across an outside 'of the first induction choke. The system can further comprise other induction chokes, other terminals extending from the device, a current sensor, a surface power source, a power transformer, a communications transformer, a surface modem, a downhole modem, a direct current power supply, and/or a power amplifier. The piping structure can comprise at least a portion of a well casing, such that the well casing acts as an electrode for making formation resistivity measurements due to the induction chokes.