Drill Bit Assembly Having Electrically Isolated Gap Joint for Measurement of Reservoir Properties

A drill bit assembly for measuring reservoir formation properties, comprising

• an electrically conductive bit head having a cutting end and a connecting end opposite the cutting end;
• an electrically conductive pin body comprising a pin body connecting end;
• an electrically insulating gap joint filling a gap between the bit head and the pin body when the connecting end and the pin body connecting end are mechanically connected to maintain the bit head and the pin body electrically separated;
• an electrical conductor extending through at least a portion of the pin body and into the bit head, the electrical conductor being conductively coupled with the bit head proximate the cutting end while being insulated from the pin body, and
• electronic equipment including measurement circuitry configured to determine an alternating current at the bit head when the alternating current is transmitted into the bit head via the electrical conductor, the alternating current being inversely proportional to a bit resistivity of the formation.

A method for measuring reservoir formation properties by a drill bit assembly comprising

• transmitting an alternating current from an alternating current signal along an electrical conductor extending through at least a portion of a pin body of the drill bit assembly and to a bit head of the drill bit assembly while the pin body and bit head are mechanically connected to each other and electrically insulated from each other by an electrically insulating gap joint;
• inducing an electromagnetic wave into a reservoir formation adjacent the bit head via the alternating current transmitted to the bit head along the electrical conductor;
• and
• determining the alternating current at the bit head, the alternating current being proportional to a bit resistivity of the formation.

A drill bit assembly for measuring reservoir formation properties, comprising

• an electrically conductive bit head having a cutting end and an opposite connecting end with a threaded head engagement section;
• an electrically conductive pin body comprising a connecting end with a threaded pin body engagement section, the threaded head engagement section and the threaded pin body engagement section being threadably engaged with an electrically non-conductive layer therebetween;
• an electrical conductor extending through at least a portion of the pin body and being electrically isolated from the pin body, the electrical conductor having a first end electrically coupled to the bit head and a second end in electrical communication with an alternating current signal to enable transmission of an alternating current into the bit head, thereby inducing an electric current into a reservoir formation adjacent the bit head, and
• electronic equipment including measurement circuitry configured to determine the alternating current at the bit head.