Intelligent Data Logger (IDL)

Star-Luck offers the most advanced capillary tubing pressure monitoring data logger on the market. The Star-Luck data logger corrects for changes in gas column weight for every data point collected. Traditional data loggers used for this type product use a single pressure multiplier factor to correct from surface gauge to BHP. In order to obtain accurate BHP using a capillary tubing pressure measurement system, the weight of the gas column must be added to the surface recorded pressure measured at the top of the capillary tube. In order to determine the column weight of the gas used, the density of the gas must be determined for the system temperature and pressure. As pressure and temperature of the wellbore change, the density of the gas changes, and thus the column weight of the gas changes. This change is accounted for with traditional capillary tubing data logger systems by using a single pressure multiplier to correct from surface to BHP based upon a pre-determined expected “average” temperature and pressure. The effect of wellbore pressure change on the gas density has the biggest effect on calculated BHP accuracy. As wellbore pressure increases or decreases, gas density increases or decreases resulting in an increased or decreased gas column weight. Use of the traditional single multiplier concept can cause BHP to be calculated with more error than necessary. The Star-Luck EDPMS data logger avoids this error by correcting the gas density and the column weight for each new pressure point collected. When wellbore conditions are in a steady state condition, the temperature change will be very small, but pressure can easily change by 10, 20 and more psi in cycles as produced fluid cuts change due to slip velocities. Without the dynamic recalculation capability of the Star-Luck data logger calculated BHP accuracy can drift by several psi during these pressure cycles. When a pressure build-up survey occurs, bottom hole pressure increases and average wellbore temperature decreases. Without the capability of Star-Luck’s EDPMS data logger correcting for density based upon pressure change, calculated BHP build-up pressure can become inaccurate by as much as 10 to 20 psi. Minimal pressure still occurs to to temperature change.