Studies of the hydrodynamic connection presence between the terrigenous bobrikovian and carbonate tournaisian objects on the basis of the geological‑technological model of the site of the field

Abstract

The authors suggest improvement of oil deposit development systems in Tournaisian and Radaevskian-Bobrikovian sediments in zones of erosion incisions with permeable types of reservoirs using the example of the Ashalchinsky oilfield. Indicator studies were conducted in the experimental section of the Ashalchinsky field in 2014 to determine the hydrodynamic connection between the terrigenous Bobrikovian deposits and carbonate Tournaisian deposits. The presence of an indicator in the production well stock in the Radaevskian-Bobrikovian sediments inside the incision, when injected into the carbonate Tournaisian deposits over the side of the incision, indicates that there is hydrodynamic connection between the enclosing Tournaisian carbonates and the terrigenous Bobrikovian-Radaevskian formations that form the incisions. It follows that the filtration from the carbonate reservoir into the terrigenous, both laterally and vertically, occurs faster and more intensively when the terrigenous reservoir is imposed to the carbonate reservoir in the incision zone. In order to confirm the presence of a hydrodynamic connection between the terrigenous Bobrikovian and carbonate Tournaisian objects, modeling studies were carried out to design the development of the site of the field. Based on the results of geological and technological modeling, it was revealed that the accumulated oil production from the wells of the Radaevskian-Bobrikovian production well stock may exceed the average well stock by 1-3 times.

Keywords

• hydrodynamic connection
• carbonate
• terrigenous reservoirs
• erosion incisions
• oil recovery coefficient
• indicator studies
• fluorescein
• filtration current lines