METHOD FOR DEVELOPMENT OF OIL FIELD AT FINAL STAGE WITH THE HELP OF FORCED WITHDRAWAL Russian patent published in 1998 - IPC

FIELD: oil producing industry; attainment of final recovery of oil with use of existing well stock. SUBSTANCE: method includes fluid withdrawal for a short period of time exceeding the preceding withdrawal rate. This forced fluid withdrawal is carried out in well selected from the number of wells located in zone of dome. This well is the closest to anticipated maximum absolute elevation on dome. Conditions of fluid withdrawal are established to provide for pressure gradient which exceeds the preceding pressure gradient by value: dP/dL ≥ Δγ• H, where dP is difference between pressure at inlet of dome and pressure in the point which is the projection of maximum elevation on horizontal plane; L is distance between point with known pressure values; Δγ is difference in density between formation oil and water; H is height equalling the difference between maximum elevation of dome and boundary of oil and water before use of forced fluid withdrawal. EFFECT: higher final oil recovery factor of producing formations and reduced cost of produced oil. 2 dwg