Method for Hydrodynamic Stimulation of the Bottom of a Seam

Abstract

The method can be used in the oil-producing industry for intensifying the production of oil and for increasing the intake capacity during the working of the bottom region of a seam and completion of wells. For producing pressure draw-down and repressuring cycles at the well bottom there is periodically changed the direction of flow of working liquid using controlled movement of jet pump. The value of maximal pressure draw-down is regulated, and periods of pressure draw-down and repressuring action are implemented with equal values of volumes of the inflow and the liquid pumpable into the seam in one cycle. These volumes in each subsequent cycle are increased. The cycles are continued until the increase in the values of the liquid volumes ceases. Chemical reagents are then pumped into the seam. If necessary, the cycles are repeated. The stimulation of the bottom region of the seam is completed with a pressure draw-down. 14 variants of formula.

What is claimed: 
     
         1 . Method of hydrodynamic stimulation of a bottom region of a seam comprising the steps of lowering to the well of body with jet pump, isolation of hole annulus from internal volume of flow column above the roof of pay zone, periodical change of direction of the flow of working liquid in the well for producing pressure draw-down and repressuring cycles, defining volumes of pumped out liquid at pressure draw-down and introducing fluid pulse to pay zone at repressuring, in this method direction of flow of working liquid in the well is changed at controlled movement of jet pump in the body, maximum pressure draw-down value is adjusted, by amount of volume of pumped into the seam liquid there is defined the period of repressuring action, and periods of pressure draw-down and repressuring action are implemented with equal values of volumes of the inflow and the liquid pumpable into the seam in one cycle, at that stated volumes in each subsequent cycle are increased, the cycles are continued until the increase in the values of the liquid volumes ceases, chemical reagents are then pumped into the seam, if needed these cycles are repeated and the stimulation of the bottom region of the seam is completed with a pressure draw-down. 
     
     
         2 . Method according to  claim 1 , wherein in pressure draw-down and repressuring cycles there are produced additional hydraulic pulses, whose energy is concentrated on the wall of casing column in the interval of pay zone. 
     
     
         3 . Method according to  claim 1 , wherein for changing direction of working fluid flow in the well jet pump in the body is moved remotely using wireline technique. 
     
     
         4 . Method according to  claim 1 , wherein for changing direction of working fluid flow in the well the jet pump in the body is moved automatically—using supply of working fluid into nozzle of jet pump in one direction and elastic force of spring returning jet pump in opposite direction at termination of supply. 
     
     
         5 . Method according to  claim 1 , wherein for producing pressure draw-down and repressuring cycles working liquid is supplied to the well through hole annulus. 
     
     
         6 . Method according to  claim 1 , wherein for producing pressure draw-down and repressuring cycles working liquid is supplied to the well through flow column. 
     
     
         7 . Method according to  claim 1 , wherein hole annulus is additionally isolated below lower boundary of pay zone. 
     
     
         8 . Method according to  claim 1 , wherein value of repressuring is set higher than value of rock pressure at the depth of chosen interval of pay zone. 
     
     
         9 . Method according to  claim 6 , wherein for exceeding value of rock pressure into pay zone there are pumped in breakdown agents. 
     
     
         10 . Method according to  claim 1 , wherein the process of treatment in chosen interval of pay zone the hydrodynamic parameters are registered. 
     
     
         11 . Method according to  claim 1 , wherein chemical reagents are in advance pumped in into flow column at pressure draw-down, and to the seam they are pumped in at repressuring. 
     
     
         12 . Method according to  claim 1 , wherein chemical reagents are pumped into the seam as a part of gas-liquid mixtures. 
     
     
         13 . Method according to  claim 1 , wherein stimulation of the bottom region of the seam is finished in the mode of regulated pressure draw-down with pumping out of formation fluids. 
     
     
         14 . Method according to  claim 1 , wherein stimulation of the bottom region of the seam is finished in the mode of regulated pressure draw-down by lowering level of liquid in the well. 
     
     
         15 . Method according to  claim 1 , wherein before and after hydrodynamic stimulation there is registered bottom hole pressure buildup in the interval of pay zone.