Method of enhanced oil recovery and intensification of production from oil, gas and condensate wells by means of hydromonitor radial underbalance formation penetration

Abstract

The method includes installation in a well of a high strength tubing, a mechanical anchoring device, a turning device, a sealing device, a deflector, a circulation unit, a packer and a re-entry guide, a running hydromonitor nozzle, a wellbore trajectory control module, a navigation system, work and supply coil tubing sections, a flow re-distribution device, a check valve. By aerated fluid supply into an annulus between tubing and coil tubing and running coiled tubing, hydromonitor underbalance drilling of planned length of controlled radial channel in the formation is performed. Fluid with cuttings coming out the well through annulus between tubing and casing string, cleaned at surface and circulated back. After work coil tubing section retrieval from the formation and well underbalance circulation, the deflector is re-positioned to a different plane by mechanical turning device; the working cycle is repeated for the next radial channel. Milling of windows for all radial channels is performed before drilling stage, all subsequent works performed without well killing.

1 - 5 . (canceled) 
     
     
         6 . A method of enhanced oil recovery and intensification of production from oil, gas and condensate wells with use of hydromonitor radial underbalance formation penetration, the method comprising the steps of:
 (a) milling of a separate window in a casing string for each radial channel for drilling of a radial channel,   (b) installing, in a well,   re-entry guide,   packer,   circulation unit,   disconnector,   a deflector having an internal channel passing through the deflector, wherein the deflector is configured to be spatially oriented in a lower level of radial channel drilling,   a sealing device,   a turning device,   a mechanical anchoring device, and   a high strength tubing,   (c) wellhead sealing,   (d) installing downhole equipment, the downhole equipment comprising:   a hydromonitor nozzle,   a wellbore trajectory control module,   a navigation system,   a work coil tubing section,   a flow re-distribution device,   a check valve,   a supply coil tubing section,   (e) supplying an aerated fluid into an annulus between the high strength tubing and the supply coil tubing section or supplying aerated fluid simultaneously into an annulus between the high strength tubing and the supply coil tubing section and an internal space of the supply coil tubing section or separate injection of fluid and gas into these two spaces, wherein the aerated fluid passes an annulus between the high strength tubing and the supply coil tubing section, the flow re-distribution device, the work coil tubing section, the hydromonitor nozzle and on to the radial channel forming a channel, then the aerated fluid returns with products of rock destruction to the well along the drilled radial channel and comes up on the wellhead along an annulus between high strength tubing and a casing string;   (f) degassing the fluid on a surface, cleaning the fluid of hydrocarbons and products of rock destruction, chemical treating the fluid if required and returning the fluid through a circulation into the well;   (g) passing the hydromonitor nozzle through the sealing device and through the deflector to contact a rock;   (h) hydromonitor underbalance drilling a planned length of the radial channel in a formation using the navigation system and the wellbore trajectory control module, wherein the navigation system is configured to control a position of a wellbore in the formation, wherein the wellbore trajectory control module is configured to ensure wellbore drilling along a designed route;   (i) providing a bottomhole pressure during step (h) the formation, wherein the bottomhole pressure is lower than a reservoir pressure or equal to it and is defined by fluid density reduced due to aeration and, when required, foam generation to needed values, wherein the fluid density is controlled by design ratio between gas and the fluid supplied from the surface with opportunity to change such ratio in compliance with actual bottomhole pressure;   (j) after drilling in step (h), retrieving the work coil tubing section with the hydromonitor nozzle from the formation;   (k) underbalance circulating the fluid in the well (the bottomhole pressure is lower or equal to the reservoir pressure) until a full carryover of cuttings occurs;   (l) re-positioning the deflector to a different plane via activation of the mechanical turning device,   (m) obtaining and changing a wellbore trajectory during radial channel drilling using the navigation system and the wellbore trajectory control module,   (n) repeating a working cycle comprising steps (e)-(m) for a further radial channel.   
     
     
         7 . The method of  claim 6  further comprising drilling a further level of radial channels after step (n) comprising the steps of:
 (o) retrieving the supply coil tubing section and the work coil tubing section from the well; 
 (p) controlling over pressure in the high strength tubing by means of closing check-valve included into tubing assembly; 
 (q) unsetting the mechanical anchoring device with the high strength tubing; 
 controlling over pressure in the annulus between the high strength tubing and the casing string by means of the wellhead sealing device; 
 (r) retrieving a tubing landing joint; 
 (s) setting the mechanical anchoring device with the high strength tubing; 
 (t) running the work coil tubing section with the navigation system, the wellbore trajectory control module, and the hydromonitor nozzle into the well, and 
 (u) performing steps (d)-(n). 
 
     
     
         8 . The method of  claim 6 , wherein step (a) comprises full-circle milling of the casing string in intervals of a planned drilling of radial channel. 
     
     
         9 . The method of  claim 6 , wherein after drilling of all radial channels on the well performing following final operations:
 (v) retrieval of process equipment from the well,   (w) installation of isolating assembly above intervals of radial formation penetration, which prevents kill fluid contact with producing formation in intervals of radial penetration,   (x) running of production assembly (for flow lift or pump) without well killing in the interval of drilled radial channels.