Mansir, Hassan (COREteQ Systems Limited) | Rimmer, Michael (COREteQ Systems Limited) | Waldner, Leon (CNOOC International) | Graham, John (Suncor Energy) | Hong, Claire (Cenovus Energy) | Wycislik, Kerry (Cenovus Energy) | Duong, Bruce (Alberta Innovates)
The development of a High-Temperature Permanent Magnet Motor (PMM) was initiated with the main objective to bring forth a technical solution to significantly increase temperature capability and run life of ESPs in Steam Assisted Gravity Drainage (SAGD) beyond current technology. This is in response to operators needs for improved safety margins and increased production rates. Existing ESP motor technologies are limited to approximately 300 C internal motor winding temperatures, driven by the available motor electrical insulation systems. The use of PMMs in SAGD was also prohibited by the availability of magnet materials capable of operating in such temperatures, without partial or full demagnetization. The project's aim is to break this barrier and extend internal temperatures to 350 C and beyond, allowing well ambient temperatures to be pushed beyond the 260 C downhole environment. In addition, for assurance of motor reliability, rigorous and methodical design validation and qualification testing of basic materials, components, sub-assemblies were undertaken.
The water recovered from hydraulic-fracturing operations (i.e., flowback water) is highly saline, and can be analyzed for reservoir characterization. Past studies measured ion-concentration data during imbibition experiments to explain the production of saline flowback water. However, the reported laboratory data of ion concentration are approximately three orders of magnitude lower than those reported in the field. It has been hypothesized that the significant surface area created by hydraulic-fracturing operations is one of the primary reasons for the highly saline flowback water.
In this study, we investigate shale/water interactions by measuring the mass of total ion produced (TIP) during water-imbibition experiments. We conduct two sets of imbibition experiments at low-temperature/low-pressure (LT/LP) and high-temperature and high-pressure (HT/HP) conditions. We study the effects of rock surface area (As), temperature, and pressure on TIP during imbibition experiments. Laboratory results indicate that pressure does not have a significant effect on TIP, whereas increasing As and temperature both increase TIP. We use the flowback-chemical data and the laboratory data of ion concentration to estimate the fracture surface area (Af) for two wells completed in the Horn River Basin (HRB), Canada. For both wells, the estimated Af values from LT/LP and HT/HP test results have similar orders of magnitude (approximately 5.0×106 m2) compared with those calculated from production and flowback rate-transient analysis (RTA) (approximately 106 m2). The proposed scaleup procedure can be used as an alternative approach for a quick estimation of Af using early-flowback chemical data.