Abstract:
Enhanced horizontal drilling systems and methods encompass the production of crude oil from wells drilled from a subterranean production facility. This approach has the location of the well head below the oil reservoir to improve flow rate and recovery due to the consistent voiding of fluids by gravity flow within the well bore to the well head allowing well bore production pressure to achieve extremely low fluid pressure or even a vacuum of up to 15 PSI. This method increases oil recovery rate and factor, and lowers production costs. The present method is production of shallow crude oil by way of long horizontal or near horizontal boreholes drilled and serviced from a subsurface workroom. The subsurface workroom serves as both the drilling platform and the place to which production is centrally accumulated from the wells. Oil is collected in a central facility and is then lifted to the surface utilizing pumps. The method allows for maximum control and range of borehole pressure, elimination of costly down-hole pumps and the introduction of production enhancing devices within the production stream such as in-hole injection of heated diluent.

Description:
This application claims the benefit of U.S. Patent Application Serial No. 60/204,793 filed May 16, 2000 and entitled METHOD AND APPARATUS FOR HYDROCARBON SUB-SURFACE RECOVERY. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to well arrangements for sub-surface fluid hydrocarbon production. 
     Techniques for hydrocarbon production are well known in the prior art, including conventional drilling techniques. The reference to “hydrocarbon” herein is to fluid and gaseous hydrocarbons, such as crude oil and natural gas. However, under certain circumstances, conventional drilling techniques are not efficient to tap into a reserve of hydrocarbons. To tap into such reserves, “oil mining” techniques have been developed, wherein a vertical or horizontal shaft is bored directly into, or in proximity to, the reserve. A drill room is excavated in the shaft, and horizontal wells, which may be slightly inclined, are bored from the drill room into the reserve. The wells allow for drainage of fluids into a common location, where the oil is transported by pump, or other device, to the grade surface. 
     The typical porous formation to which this method and device relate is a porous oil and gas bearing strata entrapped underground between a fluid impermeable cap rock above and a fluid impermeable stratum below. The typical desired fluid is hydrocarbon. The present invention relates to a method and a system which solves or avoids problems associated with prior art methods and systems used to recover desired hydrocarbons, such as oil or gas, from oil and gas bearing strata, which prior art is characterized by tunneling within or below the porous formation and drilling into the sands so that the desired fluid drains by the force of gravity into collection pits located on the floor of the tunnel. 
     Prior art methods and systems for using mine shafts or tunnels with oil drain pits for collecting oil drained form oil sands by the force of gravity have typically been called “oil-mining” systems or methods. In one early method, tunnels were driven horizontally through the impermeable cap rock above the oil bearing sand and square pits were dug vertically through the tunnel floor to the oil bearing sands a few feet below. The oil drained into these pits and was lifted periodically by a pneumatic device into a pipeline extending to surface tanks. This system was used in the Pechelbronn field near Hanover, Germany and is disclosed in G. S. RICE, U.S. BUREAU OF MINES. 
     Another variation of this method is known as the Ranney oil-mining system and is disclosed in L. C. UREN, PETROLEUM PRODUCTION ENGINEERING: OIL FIELD EXPLOITATION, 3d Ed. McGRAW-HILL (1953). In this system mine galleries or tunnels are driven in impermeable strata above or below the porous formation of oil bearing sand and holes are drilled into the porous formation at short intervals along these galleries. Fluid is withdrawn through pipes sealed into the drilled holes and is pumped to the surface through a system of drain pipes in the galleries. 
     Another method which has been proposed for mining oil from partially drained oil bearing sands involves drilling a vertical mine shaft through the porous formation and drilling long slanting holes radially in all directions from the shaft bottom into the oil sands. The oil was to drain from the sand through the radial slant holes into a pit or sump at the bottom of the shaft and was to be pumped to the surface. 
     There are problems associated with these prior art oil-mining systems. For example, where high pressure gases may be present in the porous formation the prior art methods may be ineffective because either the gas will escape directly into the tunnels, galleries, or shafts or the gas will force itself directly into the collection pipe system, thereby leaving the liquid unrecovered in the porous formation. 
     As can be readily appreciated, the recovery of hydrocarbon using prior art techniques is a function of many factors, including the permeability of the strata in which the hydrocarbon is located (typically sand), the multi-phase presence of other fluids (e.g., water, brine), the viscosity of the hydrocarbon, and the pressures within the well bore and external to the reserve. The use of an insufficient number of wells will not maximally recover hydrocarbon from the reserve, whereas, an excessive number of wells may not be economical. 
     SUMMARY OF THE INVENTION 
     Enhanced horizontal drilling systems and methods encompass the production of crude oil from wells drilled from a subterranean production facility. This approach has the location of the well head below the oil reservoir to improve flow rate and recovery due to the consistent voiding of fluids by gravity flow within the well bore to the well head allowing well bore production pressure to achieve extremely low fluid pressure or even a vacuum of up to 15 PSI. This method increases oil recovery rate and factor, and lowers production costs. 
     The present method is production of shallow crude oil by way of long horizontal or near horizontal boreholes drilled and serviced from a subsurface workroom. The subsurface workroom serves as both the drilling platform and the place to which production is centrally accumulated from the wells. Oil is collected in a central facility and is then lifted to the surface utilizing pumps. The method allows for maximum control and range of borehole pressure, elimination of costly down-hole pumps and the introduction of production enhancing devices within the production stream such as in-hole injection of heated diluent. 
     When utilized in many low energy shallow oil fields the subject production method is projected to lower per barrel production costs, accelerate rates of oil recovery and increase total economic recovery when compared to other conventional production methods inclusive of horizontal and near horizontal wells. These cost savings are attributable to generally accepted engineering concepts that profess that oil production is subject to the following factors: 
     There is a direct proportional relationship between the amount of borehole surface area within the productive portion of the reservoir and the amount of fluid or gas produced. 
     Fluid and/or gas migration (flow) within the reservoir to the borehole is a direct result of the reservoir pressure exceeding the borehole pressure (differential pressure). 
     Fluid and/or gas migration within the reservoir to the borehole increases as differential pressure increases and declines as differential pressure declines. 
     As migration distances increase total economic oil recovery decreases. 
     Any production method that reduces the cost of the well bore surface area within the productive portion of the reservoir is desirable because the more borehole surface area within the production area the greater the recovery factor. Additionally any method that reduces migration distance to the borehole is desirable. The subject method increases borehole surface area and reduces migration distance within a given production area. The increased borehole surface area allows higher recovery rates and optimizes differential pressure. When compared with conventional horizontal drilling methods the present method may save up to 60% of the combined capital and operations cost to produce a like amount of oil or gas for a like period of time. However, the subject method also may increase the recovery factor by up to 100% resulting in a dramatic increase in resource efficiency. 
     The potential savings offered by the method result from the following factors: 
     The borehole is located almost entirely within the productive portion of the reservoir. 
     The borehole is all drilled from a central location eliminating the cost of replicated support apparatus and the cost to break down, move and erect the drill rig. Cost is further reduced by the ability to use inexpensive proven drilling technology. 
     Conventional boreholes are not produced in a static environment. As reservoir pressures approach zero the well has to be more frequently evacuated because the fluid column within the borehole more quickly reaches equilibrium with the reservoir pressure; hence flow stops. Because the well bore is drained to a central collection point the method allows for static production conditions down to 15 PSI vacuum pressure hence total economic recovery is increased. 
     The production geometry reduces the migration distance; hence total economic recovery is increased. 
     Consolidation of surface facilities further reduces operating expenses. 
     environmental savings due to improved monitoring and centralization of production facilities making discovery and remediation of discharge events more effective. 
     Conventional vertical and horizontal wells require down-hole pumps to lift the oil when fluid column from the reservoir to the surface exceeds reservoir pressure. (This is the case at some point in the life of all wells.) The maintenance of the down-hole pumps is expensive. Frequent pulling operations utilizing work-over rigs to retrieve and replace the pumps are required to keep the wells producing. These pulling operations are quite expensive and contribute significantly to operating costs and increases down-time and lost revenue. The subject method requires no down-hole pumps or other down-hole servicing. All pumping is done through large reliable and efficient pumps centrally located in the subsurface drill room that are easily serviced. 
     The following forecast environmental benefits are derived from the production methods: 
     1. Reduction of surface disturbance by 90%+. 
     2. Consolidation of production facilities and reduction of surface communication. 
     3. Reduction in reclamation effort. 
     4. Elimination of cross-communication of fluids within the well bore as wells cross various formations. 
     5. Dramatic increase in recovery per acre results in improved trade-off when considering surface disturbance. 
     6. Central drilling location provides improved economics of scale for more effective treatment of drilling wastes and by-products. 
     7. Central location of all facilities makes twenty-four hour monitoring of entire production facility economically possible. Non-stop monitoring allows for quicker discoveries of leaks, less environmental damage and lower cost environmental remediation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a graph of specific productivity indices plotted as a function of reservoir permeability; 
     FIG. 2 is a graph of oil recovery versus well spacing; 
     FIG. 3 is a schematic of a partial layout of a well arrangement; 
     FIG. 4 is a schematic of a complete well arrangement; 
     FIG. 5 a  is a plan view of the turntable; 
     FIG. 5 b  is a section view of the turntable; 
     FIG. 6 a  is a plan view of the thrust-block; 
     FIG. 6 b  is a section view of the thrust-block; 
     FIG. 7 a  is a schematic of the present invention employing a heated annulus with diluent injection; 
     FIGS. 7 b  and  7   c  are detail views of FIG. 7 a;    
     FIG. 8 a  is a schematic of the present invention employing a heated annulus with recirculation and reverse flow; 
     FIGS. 8 b  and  8   c  are detail views of FIG. 8 a;    
     FIG. 9 a  is a schematic of the present invention employing a heated annulus with recirculation and normal flow; 
     FIGS. 9 b  and  9   c  are detail views of FIG. 9 a;    
     FIG. 10 is a schematic of the BHA deployment lubricator; 
     FIG. 11 is a schematic of the fluid return apparatus; 
     FIG. 12 is a schematic of another embodiment of the fluid return apparatus; 
     FIG. 13 a  is a schematic of the coiled tubing raceway; 
     FIG. 13 b  is a detail view of the shaft of FIG. 13 a ; and 
     FIG. 14 is an exposed view of the primary traction device. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention includes a method of arranging wells for sub-surface, hydrocarbon production, and an arrangement formed in accordance with the method. Reference herein to “sub-surface” production techniques includes the oil mining techniques discussed above, as well as other techniques, including the drilling devices specific to sub-surface production. To this end, the inventors herein have developed a maximum well pattern spacing (MWPS) coefficient for determining an appropriate well spacing (WS) for wells in a given arrangement. Using typical values associated with conventional wells, it is preferred that a maximum well spacing of 24.6 acres be used in arranging wells. 
     Relying on the WS coefficient, an exemplary arrangement of wells has been created, wherein wells of different lengths are bored from a vertical shaft. Preferably, the wells are of three different lengths, with wells of each length being evenly spaced about the vertical shaft. It is also preferred that the furthest extent of each well be perforated over a predetermined length to achieve hydrocarbon recovery. The perforated sections, however, are spaced from the vertical shaft. 
     Darcy&#39;s law is a common equation used throughout the oil industry. This law is a quantitative expression that describes the flow of fluids through a reserve. The general formulation of his law is given in linear coordinates by equation 1. 
     
       
           v =−( k dp )/(μ dl )  Equation 1  
       
     
     where 
     v—velocity of flow 
     μ—viscosity of the fluid 
     k—permeability of the material 
     dp/dl—pressure gradient 
     In current reservoir engineering practice, Darcy&#39;s law has been extended for the simultaneous flow of more than a single liquid. Equation 2 represents steady-state radial flow from an external boundary to a well bore. Other geometry could be demonstrated, but for purpose of this description radial flow is provided. 
     
       
           q   i =7.07 k   ri   k   a   h ( P   e −P w )/(μ i   ln (r e /r w ))  Equation 2  
       
     
     where 
     q i —flow rate of liquid phase i (i can be o for oil, or w for water), bbl/day 
     k ri —relative permeability of phase i, dimensionless 
     k a —absolute permeability of rock, darcies 
     h—thickness of the pay zone, feet 
     P e —external boundary pressure, psia 
     P W —well bore pressure, psia 
     μ i —viscosity of phase i (i can be o for oil, or w for water), centipoises 
     r e —radius of the external boundary, feet 
     r w —radius of the well bore, feet. 
     Equation 3 describes the case for the radial flow of oil in a reserve under steady-state conditions. 
     
       
           q   o =7.07 k   o   h ( P   e −P w )/(μn(r o /r w ))  Equation 3  
       
     
     where 
     o—denotes the oil phase 
     k o —K 10 , K a  darcies, K ro  is a relative value for oil and K a  is an absolute value. 
     According to the Petroleum Production Handbook, the ability of a well to produce is usually determined by the use of a “productivity index.” The use of the productivity index was first mentioned around 1930. 
     Relying on equation 3, the productivity index (PI) is defined by equation 4. As stated by the Petroleum Production Handbook, equation 4 indicates that the productivity index should be a function of the formation characteristics, fluid characteristics, and system characteristics of a reserve. 
     
       
           PI=q   o   /ΛP 7.07 k   a h/μ o 1 r   o   /r   w   Equation 4  
       
     
     where, ΛP=P 3 −P w . 
     As shown in FIG. 1, productivity indexes were employed to determine reserve permeability in the prior art. FIG. 1 shows that actual data trends differed from theoretical analysis. The results however are sufficiently accurate for engineering evaluation. 
     The variables of equation 3 can be rearranged in the form of equation 5, 
     
       
           q   o μ o /[7.07 k   o   h ( P   e   −P   w )]=/(1 n ( r   c   /r   w ))  Equation 5  
       
     
     A well spacing productivity index (WSPI) can be defined from equation 5 as shown by equation 6. 
     
       
           WSPI= 1/(1 n ( r   c r w ))  Equation 6  
       
     
     Since r c  is a function of the reserve flow boundary and r w  is essentially a constant for a fixed well size, equation 6 describes a well spacing coefficient based on a radius of drainage. 
     Using equation 6, any WSPI can be calculated for a given r c . 
     Well spacing (WS) can be determined by equation 7 using the radius of drainage of equation 6. 
     
       
           WS=πr   c   2 /43560  Equation 7  
       
     
     where, 
     WS—well spacing, acres 
     π—3.1241593 (a constant) 
     r c —radius of the external flow boundary. 
     Also, cumulative oil recovery is a function of oil production rate as given by equation 8, 
     
       
           Np−f ( q   o )  Equation 8  
       
     
     where, 
     N p —cumulative oil production, bbs 
     q 0 -oil production rate, bbl/day. 
     Since cumulative oil recovery is a function of oil production, then cumulative oil recovery is a function of the well spacing productivity index (WSPI) as defined by equation 9. 
     
       
           Np =f ( WSPI )  Equation 9  
       
     
     The graphical results for determining well spacing as a function of the area of oil produced is given in FIG.  2 . This figure shows that as the well spacing is reduced to a very small value, the amount of oil produced from that given area increases. 
     FIG. 2 also shows that as WSPI approaches a minimum, the well spacing approaches a maximum. For purposes herein, a maximum well spacing is defined as where a cumulative oil recovery (N p ) increase becomes insignificant with a decrease of well spacing. An insignificant increase in oil recovery is preferably defined as less than two percent with a change in well spacing of 3 acres. With these parameters, this provides a maximum well spacing of 24.6 acres. This value is defined as the maximum well pattern spacing (MWPS) which is theoretically independent of a reserve&#39;s physical properties. 
     In viewing FIG. 2, a well spacing greater than MWPS does not provide any beneficial results as a function of oil recovery. Also if the well spacing is reduced from MWPS, the cumulative production for a given area may be further increased. However, the increase in production does not economically justify the greater number of wells required for production i.e. the production of each well is not economically increased. 
     Relying on a maximum well spacing of 24.6 acres, the inventors herein have prepared an exemplary arrangement of oil wells. By way of non-limiting example, referring to FIGS. 3 and 4, a well arrangement for sub-surface hydrocarbon production is shown. The arrangement is generally centered about a vertical shaft  10  which is formed through a grade surface. The particular angle of the shaft  10  relative to the grade surface is not critical to the practice of the invention. Generally, in a common plane, wells of three lengths,  12 ,  14 , and  16 , are bored to radiate from the shaft  10 , wherein the wells  12 ,  14 ,  16  can be inclined. 
     The wells  12  are of the shortest radius. In the depicted arrangement, each of the wells  12  is formed with a 900′ fluid conveying section  20 , which may be for example, a 3½ inch diameter pipe. Extending from each of the fluid conveying sections  20  is a production section  22 , which is preferably a 2000′ tubular section that is perforated for hydrocarbon recovery. As such, the wells  12  each have a total length of 2,900′. It is also preferred that eight of the wells  12  be provided, and the wells  12  be evenly spaced about the shaft  10 , with angular separations of 45 degrees. 
     The wells  14  and  16  are formed in similar fashion, but with greater radii. The wells  14  each have a fluid conveying section  24  which is 3,800′ in length, and a production section  26  extending therefrom also of 2,000′. Thus, each of the wells  14  has a total well length of 5,800′. Sixteen of the wells  14  are preferably provided and preferably disposed to be evenly spaced about the vertical shaft  10  with angular separations of 22.5° (shown in FIG. 3 as 22° 30′). 
     The wells  16  are each formed with a fluid conveying section  28  that is 6,700′ long, and a production section  30  of 2,000′ extending form the end thereof. The total length of each of the wells  16  is 8,700′. It is preferred that twenty-four of the wells  16  be provided, and that the wells  16  be evenly spaced about the vertical shaft  10  at 18° intervals. 
     It is preferred that the production sections  22 ,  26 ,  30  be spaced from the vertical shaft  10 . 
     FIG. 4 depicts a full layout of the wells  12 ,  14 ,  16  about the vertical shaft  10  in the disclosed arrangement. As shown schematically in FIG. 4, each of the respective production sections  22 ,  26 ,  30  of the wells  12 ,  14 ,  16  is associated with a production area A. As can be readily appreciated, the production areas A for the various wells  12 ,  14 ,  16  will overlap to certain degrees. The MWPS calculated above of 24.6 acres, is applied, to the arrangement of FIGS. 3 and 4, wherein at each point along the production section  22 ,  26 ,  30  of each respective well  12 ,  14 ,  16 , the well spacing is 24.6 acres. For example, at point S, the well spacing of 24.6 acres defines an area K of 24.6 acres in which no production section of a neighboring well is located. Likewise, the point S π  also lies in an area K of 24.6 acres in which no production sections of adjacent wells are located. However, point S m  lies in an area K of 24.6 acres which overlaps the areas K of points S and S m . Overlapping areas K of points S, S m , S π  on the same production section are acceptable. Overlap of the areas K of different production sections are not acceptable. 
     The well arrangement described herein, as well as the calculation technique disclosed above, result in a planar arrangement that does not take into consideration the depth of a reserve. 
     In other words, referring to FIG. 4, the depth of a reserve, as measured in a direction perpendicular to the plane of FIG. 4, may be 100′ or 5,000′. The actual depth does not affect the arrangement. It may be that under certain circumstances, where hydrocarbons are being produced from a deep reserve, that multiple tiers of wells can be used formed at different depths of the vertical shaft. 
     The present invention also encompasses coiled tubing technology to drill and case the boreholes for the projects. Heretofore, drilling from subterranean drill stations has been accomplished with screw pipe. Screw pipe drilling may be problematic in pressure zones greater than the extremely low PSI environment contemplated. Well control and safety concerns make coiled tubing a preferable alternative to screw pipe drilling. Furthermore, the inherent high production rates of coiled tubing operations are well suited to a site where hundreds of thousands of feet of slim-hole lateral drilling may be drilled from a single location. Low-pressure shallow reservoirs are often best drilled in an under-balanced condition, a job best suited for coiled tubing. The combined economics and technical advantages of coiled tubing make this technique the preferred method of borehole development. Although coiled tubing day rates are comparatively high, the high production rate from a single set up promise considerable savings in completion cost. 
     Coiled tubing drilling using the present invention includes several specialized devices, including turntable, thrust-block, heated annulus, deployment lubricator, fluid return system, coiled tubing raceway, primary traction device, and service window, as shown in FIGS. 5 a - 14 . Referring to FIGS. 5 a - 6   b , turntable  32  orients a coiled tubing drill string  34  on the horizontal azimuth. The drill string  34  is converted from a true vertical alignment to a horizontal or near horizontal alignment through a thrust block  36 . The thrust block  36  attaches to the turntable  32  using conventional fasteners; proposed bolt-hole alignment is detailed in FIGS. 5 a - 5   b . The turntable  32  aligns the drill string  34  as it exits the thrust block  36  to the desired location on the compass rose (azimuth) by rotation of the attached thrust block  36 . The pins operate on a simple shear concept. The thrust-block  36  allows for coiled tubing drilling from a single surface location in a near infinite number of horizontal directions by utilizing a sub-surface horizontal orientation device. Turntable  32  also includes collar  38  (FIGS. 6 a  and  6   b ) to allow 360° rotation within the drill room. Blow out preventer (BOP) 74, described in relation to FIG.  10  and primary injector  100 , described in conjunction with FIGS. 12 and 14, are arrayed coaxially with drill string  34 , on turntable  32 . BOP 74 allows deployment of bottom hole assembly (BHA) into a live well in the inverted or horizontal positions. Primary injector  100  is located on turntable  32  in a subterranean drill room and provides force on the bit by means of coiled tubing unit  110  with a steerable drilling assembly. 
     Referring to FIGS. 6 a - 6   b , thrust-block  36  is intended to alter a coiled tubing drill string  34  from a vertical to horizontal or near horizontal alignment within a short turn radius, 20 feet or less, by the use of a mechanical device. The mechanical device is intended to take advantage of the inherent elasticity (temporary deformation) and plasticity (permanent deformation) of coiled tubing drill string  34  that permits bending of the coiled tubing drill string  34  (pipe) in a short radius without structural degradation. The thrust-block  36  is intended to alter the drill string  34  alignment from vertical to horizontal or near horizontal in a radius of as little as ten feet and as great as thirty feet. The alignment change is achieved by the coiled tubing drill string  34  being fed and or pulled through a curved or arcuate portion of thrust-block  36  having (raceway)  48  friction reduction devices  50  that may consist of rollers, bushings and or collars  112  coated or consisting of low friction materials such as nylon and teflon. The compressive forces on the coiled drill string  34  are great enough to bend the drill string  34  without structural degradation within the thrust-block  36 . The thrust-block  36  is capable of withstanding lateral forces that may develop as a result of moment-arm. The thrust-block  36  is unique in that it bends coiled tubing to near minimum radius in a below surface location. This ability allows for remotely operated coiled tubing drilling and service operations to be conducted from the surface through a subterranean drill station and horizontal or near horizontal well bores. 
     Referring to FIGS. 7 a - 9   c , heated annulus  52  improves extractability of heavy viscous crude oils from the well bore. The heated annulus  52  with diluent injection of FIGS. 7 a - 7   c  is intended to reduce oil viscosity by API gravity reduction and temperature increase. Oil viscosity is in direct inverse proportion to ease of extraction. Hence as viscosity increases difficulty in extraction increases. The heated annulus  52  with diluent injection is a unique device that allows introduction at well bore terminus  54  (TD-meaning “total depth”) diluent and the induction of heat. The diluent is to be heated to its maximum permissible temperature without thermal decomposition and pumped to TD for injection in the production stream. An injection line  56  is placed within the well bore casing  58  at near full well bore length. Thermal transfer from the diluent heats the annulus that is positioned in the production stream within the well bore. Thermal transfer from the annulus  52  heats the production stream (crude oil mixed with diluent). The diluent, a kerosene or equivalent, is a high API gravity (light) hydrocarbon. When the diluent is mixed with the heavy (low API gravity) crude oil gravity increases and the production stream viscosity is reduced. 
     The heated annulus  52  without diluent injection (normal and reverse flow recirculation method) of FIGS. 8 a - 9   c  is likewise intended to improve extractability of heavy viscous crude oils from the well bore. The device with recirculation is intended to reduce oil viscosity by temperature increase. Oil viscosity is in direct inverse proportion to ease of extraction. Hence as viscosity increases difficulty in extraction increases. The heated annulus  52  with recirculated hot oil is a unique device that induces heat to the production stream. The annulus heating fluid is to be heated to its maximum permissible temperature without thermal decomposition and pumped to and recirculated from TD. Unlike the embodiment of FIGS. 7 a - 7   c , the annulus  52  includes a concentric tubing  60  within the well bore casing  58  at or near full well bore length. Thermal transfer from the annulus heating fluid heats the annulus  52 , which is positioned in the production stream within the well bore. Thermal transfer from the annulus  52  heats the production stream (crude oil). Also included in the three embodiments of FIGS. 7 a - 9   c  are diluent tank  62  connected to pump  64 , and heat exchanger  66  connected to both pump  64  and boiler  68  with the fluid flow from heat exchanger  66  entering annulus  52 . In FIGS. 7 a - 7   c , flow entering annulus  52  passes there through into well casing  58  and then through stripping plant  70  and into the crude production line. In FIGS. 8 a - 8   c  and  9   a - 9   c , flow entering annulus  52  also exits annulus  52  and returns to diluent tank  62 . 
     Referring to FIG. 10, deployment lubricator  72  provides well control on a live well whilst allowing introduction of rigid drill tools into a subterranean well head. The tight radius of thrust-block  36  prohibits placement of rigid tools within the drill string  34  prior to induction in thrust-block  36 . The lubricator  72  functions as a pressure lock that allows for introduction, connection to and servicing of rigid tools (bottom hole assembly) at the subterranean well head. The lubricator  72  accomplishes this by creating a chamber within the horizontal well section  76  adjacent to the blow-out-preventer (BOP)  74  that can be isolated from well bore pressure by the use of a globe valve  78 . The lubricator  72  has a safety mechanism redundant to the BOP  74 , a guillotine or shear  80 , with sufficient force to sever any tool or device within the receiver  72  and permanently close the well. When the subterranean safety valve  78  is open the well functions as any ordinary section of the well bore and freely allows movement of drill tools and drill string  34 . When the subterranean safety valve  78  is closed the lubricator  72  is isolated from well bore pressure; hence fluids and pressure within the lubricator  72  can be relieved through valves providing air venting and fluid drainage  82 ,  84 ,  86 . When the lubricator  72  pressure is in equilibrium with atmospheric pressure the receiver  72  can be safely opened to the subterranean drill room allowing access to the rigid tools (bottom hole assembly). 
     Kill line  79  is a pump-in port that “kills” the well should a well control situation occur during drilling. Stuffing box  83  provides a dynamic and static pressure on drill string (coiled tubing)  34  while being deployed into or out of the well bore. Drill motor  85  causes rotational motion of drill bit  87 , and orienter  89  ensures alignment of drill bit  87 . 
     FIG. 11 shows the operation with one traction device (primary injector  100 ) being used at surface only and the thrust block  36  and BOP  74  stack being subterranean within the drill room. All tool deployment is done from within the drill room. Referring to FIG. 11, a curved raceway  48  of thrust block  36  provides a conduit for the string  34  in coiled tubing reel  100  to be deployed from surface to the drill room. The drill string  34  enters the drill room via a raceway extension and travels through the thrust block  36  set at the appropriate angle to enter the well bore. The bottom hole assembly is deployed within the drill room at the service window and connected to the coiled tubing string  34 . The tools and the string are then run in whole through the blow out preventers  74  into the well. Fluid circulation is pumped by pump  101  through the coiled tubing string  34  from surface through the bottom hole assembly and returns are received into the drill room and pumped back to surface via a pump located within the drill room. All returns are then transported to surface where the cuttings are removed and the fluid can be reused or disposed. All forces snubbing or pulling during this operation are transmitted via the injector at surface where the cuttings are removed and the fluid can be re-used or disposed. All forces snubbing or pulling during this operation are transmitted via the injector at surface (primary injector  100 ). All tool deployment and safety barriers are within the drill room, which is subterranean. 
     Referring to FIG. 12, the description of elements common to both FIGS. 11 and 12 and previously described with reference to FIG. 11 is incorporated herein. Unlike the embodiment of FIG. 11, secondary injector  111  is present in addition to primary injector  100  in the laity embodiment of FIG.  12 . Also, service window  98  is present. Service window  98  is a device for the containment and support of the primary injector  100 . The purpose of the service window  98  is to isolate the primary injector device  100  from the return drill fluid stream and to pack-off fluid pressure and drain fluids from the primary injector device  100 . This allows access and servicing of the primary injector  100  in atmospheric condition without withdrawal of the drill string  34 . (Cessation of drilling operations is required during servicing.) During drilling operations the service window  98  isolates the primary injector  100  from the drill fluid return stream by diverting the drill stream return through a valved flow cross  102 . Solids are retained or reintroduced to suspension prior to entry in the by-pass by use of a venturi that increases fluid velocity. 
     Referring to FIGS. 13 a  and  13   b , gooseneck  121  supports drill string  34  between coiled tubing unit  110  and primary injector  100 . Coiled tubing raceway  108  allows the remote introduction of coiled drill string  34  to a subterranean well head from a surface mounted coiled tubing unit  110 . The raceway  108  provides directional stability for the coiled drill string  34  as snubbing (compressive) force is introduced to the drill string  34  to force the drill string  34  through the subterranean thrust block  36  and to provide drill bit force, if and when drill bit force is required. Due to its flexible nature coiled drill string  34  takes on a sinusoidal shape resulting in a helical form when compressed between the snubbing force and resistance which can be defined as further bending, drill pressure, drag and the like. The raceway  108  provides lateral support and alignment thereby minimizing transverse compression relief to the snub force required to induce the drill string  34  through the thrust-block  36  and provide drill bit force. Alignment of the drill string  34  within the raceway  108  is accomplished by the use of rollers  112  and or collars or bushings coated and or constructed with friction reducing materials such as nylon and teflon. 
     Referring to FIG. 13 b , first drill mud line  123  is a drilling fluid return line. Gas vent line  125  is a conduit from the production room to allow gas to be transported to surface facilities. Second drill mud line  127  alleviates friction pressures that would be present if only first drill mud line  123  was employed. Production line  129  is a conduit from the production room to allow the produced fluids to be transported to the surface facilities. Power conduit  131  protects the main power cable between the production room and surface. Kill line  133  is a port through which the well can be “killed” should a well control situation occur during drilling. Communication conduit  135  houses all telemetry, control and telephone cabling between the surface and the drill room/production room facilities. Water line  137  allows water to flow from the surface to the drill room/production room. Compressed air line  139  sends air from the surface to the drill room/production room facilities. 
     Referring to FIG. 14, primary injector  100  applies force to the drill bit from a location below surface and remote from the coiled tubing unit  110 . The primary injector  100  is intended to be synchronized to the secondary injector  101  located at the surface in immediate proximity to the coiled tubing reel of unit  110 . The primary injector  100  will provide tension on the drill string  34  (coiled tubing) as it is extracted from the subsurface thrust-block  36  and compression on the drill string  34  between the drill bit and the traction device. Primary injector  100  has a center bore  116  through which drill string or coiled tubing  34  passes. A hydraulic motor  118  actuates gripper blocks  120 , which contact drill string  34  in center bore  116 , by means of chain  122  and skate ram  124 . At one end of primary injector  100 , stripper  126 , cutters  128  having blind rams  130 , and slips  132  having pipe rams  134  are arrayed. The primary injector  100  provides the advantage of shortening the distance between the force upon the drill bit and the drill bit when compared to surface level injection. This condition is advantageous due to the physical properties of drill string  34  and its inherent propensity towards elasticity. The tubing assumes a sinusoidal shape when sufficiently compressed between the snubbing force and resistance. The force at which sinusoidal geometry takes place reduces as distance between the snubbing force and resistance increases. Hence relocation of the force from the surface to the subsurface increases the distance at which horizontal borehole can be drilled utilizing coiled tubing. The placement of the primary injector  100  “down-hole” from the transition moment from vertical to horizontal also eliminates the bending resistance between the drill bit and the traction device. Likewise the total horizontal distance that can be drilled utilizing coiled tubing is increased. The primary injector  100  is operable as follows: 
     1. Horizontal operation 
     2. Operation below surface and remote from the coiled tubing source 
     3. Operation in synchronization with an above ground unit 
     4. Operation for the purpose of pulling (tension) the coiled tubing from vertical to horizontal or near horizontal alignment.