DYNAMICS OF HYDRODYNAMIC PRESSURE IN THE WELL WITH PACKER SUCKER-ROD WELL PUMPS

A study is made of the possibility of using sucker-rod well pumps for oil withdrawal from the below-packer space of a producing well as a method of continuous excitation of fl uctuations of hydrodynamic pressure in the wellbore for wave action on the face zone of this well. The action of pulses of hydrodynamic pressure on the pay formation in the nearwellbore zone contributes to the cleaning of microparticles clogging the rock′s void space from it, to the development of a crack system in the rock, to the reduction in the effi cient viscosity of formation fl uids possessing viscoplastic properties, etc. This action tends to raise the effi ciency of producing wells. By mathematical-modeling methods, the author has obtained an analytical expression describing, with a high degree of accuracy, the dynamics of hydrodynamic pressure in the wellbore over one period of operation of suckerrod well pumps. It has been shown that in high-permeability formations with a formation-fl uid viscosity close to the viscosity of water, the amplitude of hydrodynamic-pressure fl uctuations in the below-packer zone of the wellbore is relatively small and is measured by values of the order of hundredth fractions of an MPa. On reduction in the permeability of reservoir rock, rise in the viscosity of the formation fl uid, and growth in the well yield, the amplitude of pressure fl uctuations grows up to ~1 MPa or more, which is responsible for the high effi ciency of wave action on face zones. The obtained results may be used to assess the effi ciency of use of sucker-rod well pumps in combination with packers to stimulate fi ltration processes in the face zones of oil-producing wells.
A study is made of the possibility of using sucker-rod well pumps for oil withdrawal from the below-packer space of a producing well as a method of continuous excitation of fl uctuations of hydrodynamic pressure in the wellbore for wave action on the face zone of this well. The action of pulses of hydrodynamic pressure on the pay formation in the nearwellbore zone contributes to the cleaning of microparticles clogging the rock′s void space from it, to the development of a crack system in the rock, to the reduction in the effi cient viscosity of formation fl uids possessing viscoplastic properties, etc. This action tends to raise the effi ciency of producing wells. By mathematical-modeling methods, the author has obtained an analytical expression describing, with a high degree of accuracy, the dynamics of hydrodynamic pressure in the wellbore over one period of operation of suckerrod well pumps. It has been shown that in high-permeability formations with a formation-fl uid viscosity close to the viscosity of water, the amplitude of hydrodynamic-pressure fl uctuations in the below-packer zone of the wellbore is relatively small and is measured by values of the order of hundredth fractions of an MPa. On reduction in the permeability of reservoir rock, rise in the viscosity of the formation fl uid, and growth in the well yield, the amplitude of pressure fl uctuations grows up to ~1 MPa or more, which is responsible for the high effi ciency of wave action on face zones. The obtained results may be used to assess the effi ciency of use of sucker-rod well pumps in combination with packers to stimulate fi ltration processes in the face zones of oil-producing wells.
Author:  A. V. Svalov
Keywords:  producing well, sucker-rod well pump, packer, wave action, well effi ciency
Page:  657