The AccuFIT service delivers high-quality data acquired during Leak Off and Formation Integrity Tests. Because information about LOT or FIT is no longer limited by surface measurements, the knowledge about real downhole pressure is improved. Technologies such as flexible resolution modes with downlink command, intelligent data compression, default sending of the downhole data after start of normal flow resumes and automatic switching to the high-resolution mode without downlink command, ensure optimal decisions for the drilling mud program, evaluation of the cement strength around casing shoe, and provision of input for pore pressure analysis, while minimizing nonproductive time.
Get the pressure profile from your formation integrity test/leak-off test (FIT/LOT), in real time, with the AccuFIT™ real-time flow-off pressure data service from Baker Hughes. By enabling pressure data to be transmitted uphole immediately after the test, the AccuFIT service improves the quality and accuracy of measurements compared to surface-based FIT/LOT methods.
FITs and LOTs are valuable methods of evaluating the maximum pressure an openhole section can tolerate. But conventional, surface-based tests are limited due to challenges with data accuracy from the cementing unit and rig pump pressure gauges. Cased hole effects—including mud compressibility, gas trapped in drilling fluid, and casing expansion—also limit the accuracy of the pressure data acquired.
The AccuFIT service resolves these challenges by providing real-time, downhole data. The service delivers an initial 60-point pressure-versus-time curve for the entire LOT/FIT interval. The profile is detailed enough to visualize the entire flow-off event immediately, and determine the leak-off pressure and breakdown pressure, if reached. It also estimates slopes for the time after breakdown pressure.
The AccuFIT service is an expansion of the current Min/Max flow-off annular pressure offering from the proven OnTrak™ and AziTrak™ tools. But while these tools required pulling out of hole (POOH) to download the flow-off annular pressure data from the OnTrak/AziTrak memory, the AccuFIT service commences initial transmission downhole, immediately after circulation resumes. No time-consuming rig downlink is required.
If higher resolution data is required for a particular time interval of interest, the AccuFIT service can “zoom in” by sending an additional downlink for 60 data points over that shorter time interval. A downlink to cancel LOT/FIT transmission can be sent downhole when the service is no longer required or enable it when needed.