Drill cuttings lag time monitoring

A system for estimating a drill cuttings lag time during a drilling operation, the method comprising:

• a surface system configured to circulate drilling fluid in a wellbore while drilling the wellbore, the circulating drilling fluid traveling downhole through a drill string and uphole through a wellbore annulus, the circulating drilling fluid carrying drill cuttings generated by the drilling to a surface location;
• a plurality of radio frequency identification device (RFID) tags configured for introduction into the circulating drilling fluid;
• first and second RFID readers, a first of the RFID readers being configured to detect the RFID tags after the introduction into the circulating drilling fluid and before the RFID tags are carried by the drilling fluid uphole through the wellbore annulus, a second of the RFID readers being deployed in the surface system at the surface location and being configured to detect the RFID tags after the RFID tags are carried by the drilling fluid uphole through the wellbore annulus;
• and
• a processor configured to evaluate a difference in detection times of selected ones of the detected RFID tags at the first RFID reader and the second RFID reader to estimate the drill cuttings lag time.

A method for estimating a drill cuttings lag time during a drilling operation, the method comprising:

• circulating drilling fluid in a wellbore while drilling the wellbore, the circulating drilling fluid traveling downhole through a drill string and uphole through a wellbore annulus, the circulating drilling fluid carrying drill cuttings generated by the drilling to a surface location;
• introducing a colored liquid tracer into the circulating drilling fluid while drilling, the colored liquid tracer being introduced into downwardly flowing drilling fluid in a downhole tool located in a bottom home assembly above a drill bit, the colored liquid tracer including a water soluble dye and being formulated to adhere drill cuttings such that it generates colored drill cuttings upon passing through the drill bit into the wellbore annulus;
• detecting the colored drill cuttings at the surface location;
• and
• evaluating a detection time of the colored drill cuttings to estimate the drill cuttings lag time.