Shut-in temperature profiles tell where the water went

Waterflood operators want to know where and how much water is going into the producing formation. Experience with the shut-in temperature profile in more than 500 water-injection wells in West Texas shows that operators need no longer wonder ''where the water went.'' Data gained from this log, coupled with known fracture problems due to primary treatments, show the operator how much net zone is being flooded. Point-of-entry information can be obtained by other types of surveys, but what happens to the water after it leaves the immediate vicinity of the well bore is what is important. Interpretations based on point-of-entry data can be misleading if large volumes of water have been injected and no response is noted at the producing wells. Interpretation techniques for the shut-in temperature profile were partially developed from data contained in more than 2,000 frac evaluation logs. These show that wells often fracture out of zone and usually fracture up the hole from 20 to more than 300 ft on most primary completions.