Abstract: Revitalizing the Clay Containing Beds at the Romashkino Oil Field

MUSLIMOV Rh., R. Z. MUKHAMETSHIN*, V. N. DOLJENKOV, E. I. SULEYMANOV

For 45 years the history of the development the main exploitation play of the unique Romashkino oil field - the multi-bed horizon D1 in the Upper Devonian,- has recorded essential changes in the structure of oil reserves. The share of hard recoverable reserves increased from 30% to 80%. The great oil reserves were obtained where the clay content, including aleurolites, is low and the middle permeable rocks (sandstones) are well developed. X-ray analysis of the finely dispersed component of clastic reservoirs from horizon D1 showed the availability of different clay minerals which can change from layer to layer under the action of natural and technological factors. Particularly, it has been the case in the layers enriched by montmorillonite (by volcanic ash).

The results of differing water composition on water displacement efficiency in reservoir conditions, from cores from 112 bed intersections, showed great decrease of this parameter (from 0.74 to 0.60) for clay-bearing, low-permeability reservoirs within heterogeneous layers during low mineralized water flooding. It is confirmed by experimental data from filtration of fresh, flushing and formation water through samples of core under laboratory conditions.

In Tatneft Company, the complex system of revitalizing the clayey beds with reserves has been realized, with the next main elements having been considered: optimization of well density, separate stimulation of beds with different characteristics, optimization of formation and botton hole pressure, consideration of irreversible rock deformation (by M.Belonin, V.Slavin), the clayey and clean reservoir relation in the section and planning, using hydrodynamic, physical-chemical and microbiological EOR. To receive greater effect from tertiary production using such complex EOR has been recommended that decreases in heterogeneous layers clay material swelling and dispersion in beds.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria