Ways of Shallow Heavy Oil Deposit Development in the Active Aquifer Environment

  • Technical Program
  • September 8, 2016
  • Palomino Room A/B
  • 9:30 am - 10:00 am

Heavy oil deposits in the Sheshminsky horizon in Tatarstan, Russia, contain huge resources of oil with viscosity up to 145 MPa*s. The main limiting factor of the thermal process for them is an extended active water oil contact. In 2006, JSC “Tatneft” started the new stage of development in the first Ashalchy heavy oil deposit by drilling and successful operating of the different kinds of SAGD wells.  Today, there are 70 SAGD pairs and 27 CSS wells in the Achalchy field. The different geological conditions, mainly, heterogeneity of water saturation in the transition zones have demanded the specific technological solutions to control steam injection and oil production. Allocation of the bounding single producers or CSS wells in the proximity of edging SAGD pairs has been tested. This solution combines both more effectively cover deposits by sweeping and the distribution of SAGD’s chamber thermal en-ergy. Water influx control by using lower dipping wells to draw water back from higher located SAGD pairs, as well as high water saturated interval insulation, by the installation of the thermal resistant gel plugs in horizontal wells before the preheat phase starts.  The solvent preflush has been successfully implemented in the injection wells to accelerate connectivity of the pair. As a result of the developed solutions, the maximum flat production was reached faster by 1.9 times, and a steam – oil ratio (SOR) was reduced by 1.2 times while a recovery rate was increased by 1.7 times.  Current SOR for the first Ashalchy deposit, which has been developed since 2006 and produced 9 000 bbl/day, is 2.7 while total field SOR is 4.6 so far.The current production of whole expanded heavy oil project for the Sheshminsky horizon counts more than 11, 000 bbl/day.