RU2013104859A - METHOD FOR OPENING PRODUCTIVE LAYER AT DEPRESSION - Google Patents

Abstract

A method of opening a productive formation in a depression, including lowering drill string with a bit and at least two containers with autonomous pressure gauges into the borehole, tying the wellhead, flushing the wellbore, and supplying the aerated drilling fluid with a gaseous, for example, nitrogen agent, to the bit after drilling washing the borehole through the cable entry into the borehole, lower the cable depth gauge to the depth in which the autonomous manometers of the drill pipe string are placed in the borehole, then conduct in the borehole studies on the establishment of drilling regimes for depression, for which, after the beginning of the circular circulation of flushing fluid with a gaseous agent in the wellbore, at least three alternating modes of supplying depression of aerated flushing fluid are created alternately: below the design pressure equal to the design pressure and above the design pressure, while at all modes measure the pressure values on autonomous and cable depth gauges, record the time and set the pressure loss in the interval from the installation site of the manometer to According to the data obtained, they analyze the bottom-hole pressure change depending on the flow rate of the flushing fluid and the gaseous agent and construct a graph of this dependence, according to which the required flow rate of the flushing fluid and the gaseous agent is established, characterized in that the mode of maintaining the given value of depression on the reservoir selected in such a way as to ensure a constant value of depression during the opening of the formation throughout the thickness, by adjusting the flow of flushing fluid and gaseously

Claims (1)

A method of opening a productive formation in a depression, including lowering drill string with a bit and at least two containers with autonomous pressure gauges into the borehole, tying the wellhead, flushing the wellbore, and supplying the aerated drilling fluid with a gaseous, for example, nitrogen agent, to the bit after drilling washing the borehole through the cable entry into the borehole, lower the cable depth gauge to the depth in which the autonomous manometers of the drill pipe string are placed in the borehole, then conduct in the borehole studies on the establishment of drilling regimes for depression, for which, after the beginning of the circular circulation of flushing fluid with a gaseous agent in the wellbore, at least three alternating modes of supplying depression of aerated flushing fluid are created alternately: below the design pressure equal to the design pressure and above the design pressure, while at all modes measure the pressure values on autonomous and cable depth gauges, record the time and set the pressure loss in the interval from the installation site of the manometer to According to the data obtained, they analyze the bottom-hole pressure change depending on the flow rate of the flushing fluid and the gaseous agent and construct a graph of this dependence, according to which the required flow rate of the flushing fluid and the gaseous agent is established, characterized in that the mode of maintaining the given value of depression on the reservoir selected in such a way as to ensure a constant value of depression during the opening of the formation throughout the thickness, by adjusting the flow of flushing fluid and gaseously about the agent on the bit, as well as regulating the bottomhole pressure by throttling the circulation on the flow line, the value of which is calculated for all types of drilling operations taking into account the stage of development of the reservoir, and for conditions of only drilled and not commissioned deposits characterized by constant reservoir pressure across the reservoir , bottomhole pressure fluctuations in statistics and hydrodynamics are compensated by throttling of the flow line, the value of which for each (i-th) type of drilling operation is determined t calculated by the formula $$R_{dR\mathrm{about}\mathrm{from}\mathrm{from}el\mathrm{and}R.\left(i\right)}=R_{Pl.}-R_{s\mathrm{but}b.\left(i\right)}$$

and for conditions of long-term exploited deposits characterized by reservoir pressure alternating with respect to the reservoir strike, the throttling pressure value is determined on-line by direct measurements of bottomhole and reservoir pressure in real time using special equipment.