Patent Publication Number: US-8985239-B1

Title: Drilling derrick and apparatus base assembly

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Applicant claims the benefit of Provisional Patent Application No. 61/461,920, filed on Jan. 25, 2011, filed by the same inventor. 
    
    
     I. BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     An improved base structure for a lower mast of a pivotal drilling rig structure provides at least two A-frame support members affixed to the rig side of the lower mast, the drilling rig structure being elevated to a point slightly forward from vertical position towards the well side, with the A-frame support members held in a drilling position by respective support member struts which apply force against the A-frame support members during use of the drilling rig structure to enhance the drilling forces applied during the drilling process. A rig side secondary locking support structure secured to an elevating drilling rig platform provides additional stability to the drilling rig structure when the drilling rig is in an operational position subsequent to the positioning of the A-frame support members and the support member struts. 
     2. Description of Prior Art 
     A preliminary review of prior art patents was conducted by the applicant which reveal prior art patents in a similar field or having similar use. However, the prior art inventions do not disclose the same or similar elements as the present improved derrick and associated apparatus, nor do they present the material components in a manner contemplated or anticipated in the prior art. 
     In U.S. Patent Application No. 2009/0272540 to Rodgers, a mobile hydraulic work-over rig is disclosed, which includes a rig having a derrick elevated on a base structure comprising containers for equipment used in association with the drilling or work-over activity, a work platform including pipe rack sections for storing pipe, with the derrick being open sided with a power cylinder at an upper end for lifting and lowering pipe section away from and into each well, and hydraulic drive cylinders for advancing the rig between wells without telescoping or pivoting the derrick into a travel position, all of the hydraulic components being operated from a central control panel on the work platform. 
     Telescoping derricks on workover rigs are disclosed in U.S. Pat. No. 7,461,831 to Mosley, U.S. Pat. No. 5,450,695 to Desai, U.S. Pat. No. 4,932,175 to Donnally, U.S. Pat. No. 4,590,720 to Reed, and in U.S. Pat. No. 4,969,776 to Bunce. More specifically, Bunce discloses an offshore rig with has extendable caissons with a topside platform, the caissons extending to the bottom of the sea floor, providing a stable working platform. Reed has a plurality of element which telescope one into another so that the derrick can be raised from a short collapsed position into an extended position by the use of four cables, one in each corner of the derrick. Donnally is a telescoping derrick that is light for easy transport and uses structure to enable the mast to be raised from a collapsed horizontal position to a vertical position by hydraulic cylinders, the mast in an retracted position and later the being telescopically raised to full height by a cable means. Mosley is relatively similar to Donnally and also the Rodgers assembly. A very established collapsible derrick tower, using a cable hoist, is disclosed in U.S. Pat. No. 1,299,261 to Taylor. 
     In U.S. Pat. No. 5,161,639 to Ice, a telescoping rig is disclosed having a safety line attached to the crown which is used to secure a worker within a harness while climbing up the derrick tower. This harness device includes a counterweight within a telescoping tube. This derrick, which is not indicated on a portable rig also appears to have two lower support fins although no function is noted for these lower fins. 
     Other patents indicate features in prior art which are hereby disclosed and improved in the present derrick and apparatus, including U.S. Pat. No. 5,697,457 to Back, which provides a drilling derrick or mast transported on a trailer of a vehicle, which is raised into a vertical position using a pivotal means and a hydraulic ram to elevate the derrick or mast from a horizontal transport position tot a vertical drilling position. In U.S. Pat. No. 4,757,592 to Reed, a method is disclosed which provides a jacking crane erecting four telescoping hydraulically powered legs used to erect a “two spaced parallel column drilling derrick.” This is built upon a mud sled platform which provides a secure stable platform upon which to build the drilling derrick. 
     A telescoping drilling rig is indicated in U.S. Pat. No. 4,932,175 to Donnally which involves a substructure pivotally connecting a lower mast section which is raised and lowered between a horizontal position and a vertical position by a power means (cable),  FIG. 5 , and an upper mast section being in sliding engagement with the lower mast section,  FIGS. 6-7 , and a guide assembly for connection between the upper and lower mast sections with foot for securing the upper mast section for telescoping movement within the guide assembly as indicated in  FIGS. 2 and 4 . 
     A variety of different A-frame structures utilized in the base of a drilling rig are demonstrated in several patents, including U.S. Pat. No. 5,794,723 to Caneer, Jr., U.S. Pat. No. 4,465,144 to Gugger, U.S. Pat. No. 4,447,997 to Delgado and U.S. Pat. No. 4,024,924 to Houck. In Houck, the A-frame is a stationary stop attaching to a table structure, which is used to buttress a standing vertical derrick. A quite similar situation is disclosed in the Delgado patent, where the A-frame is erected and affixed to the floor of the drilling rig and a vertical cable is used to raise the derrick from a horizontal position into a vertical position, with the A-frame providing a locking attachment for the derrick to maintain the vertical position. In Gugger, an A-frame structure is mounted to the rear of the derrick trailer, with the upper end of the A-frame being pivotally attached to the derrick while a piston ram elevates the derrick from a horizontal transport position to a vertical drilling position, with the derrick further held into position by a plurality of wedges or locking pins at the upper end of the A-frame and the lower end of the A-frame. A somewhat similar inclusion of an A-frame support component is used in the Caneer, Jr., apparatus. 
     Use of a top drive drilling component on a vertical drilling rig is demonstrated in several drilling rig patents, including U.S. Pat. No. 7,828,086 to Lesko, U.S. Pat. No. 7,290,621 to Orr, U.S. Pat. No. 6,913,096 to Nielsen, U.S. Pat. No. 6,412,576 to Meiners U.S. Pat. No. 6,336,622 to Eilertsen U.S. Pat. No. 6,112,834 to Barrett, U.S. Pat. No. 4,753,300 to Shaw, and U.S. Pat. No. 4,478,291 to Futros, with these top drive mechanisms developed for practical use in the oil fields in the 1980&#39;s, even though conceived as early as the 1920&#39;s, to overcome the limitations of rotary table drilling systems. These top drive systems provided a means of drilling an entire stand of drill pipe, or multiple single strands of pipe connected together, where the rotary table drilling only provided for the drilling of a single pipe strand at one time. over time, these top drive assemblies have also provided the ability to deliver drilling mud and chemicals to the drilling stem. These top drive assemblies have had difficulty with handling the connection and disconnection of drill pipe, but the moving and handling of stands of drill pipe. Another problem with top drive assemblies is that they do not efficiently provide stability against great rotational force torques sometimes applied to them while being used with a hydraulic drilling system, the higher torque being used for deeper wells or for directional horizontal drilling. The advance of the top drive apparatus is disclosed by the top drive system employed in the present invention. 
     Thus, as seen in the prior art, Futros discloses a top drive connected to a chain which uses a pulley system to divert the pressure of lifting the top drive and applying drilling pressure to the base of a drilling derrick instead of the drilling pressure being forced against the top of the derrick. Eilertson indicated the use of a lifting device having rack segments which are moved up and down by using driving gear and shifting the load handles by the lifting tackle to the bottom of the derrick. 
     A double derrick drilling rig is disclosed in the Meiners patent which provides a top drive with two opposing guide trolleys on the ends of opposing counter-torque arms which are directed against some object on each of the two derrick towers, and presumably some type of tract, since the guide trolleys appear to have some type of four wheeled rolling means on each guide trolley. More directly, a top drive integrating within a drilling rig is the subject of the Orr patent, wherein the derrick is provided with a track system on the inner surfaces of the derrick, which may be a telescoping derrick assembly, with the top drive having a plurality of pads engaging a pair of structural guide rails comprised of a pair of rectangular tubes which extend the length of the mast of the derrick assembly. The top drive is suspended from the crown by a wire being guided over pulleys to raise and lower the top drive along the length of the mast or derrick. The top drive is locked in position along the mast by lock pins during maintenance or transport. The pads on the top drive are part of a disclosed vertical “guidance and torque reaction mechanism”. 
     Most recently, Lesko discloses a guide rail system for a telescoping mast on a drilling rig which disclose a rail system on the inner portion of the telescoping mast having parallel guide tracks of tubular steel welded to the derrick, with the lower and upper mast sections each having these guide tracks,  FIG. 8 . The top drive provides an upper and lower set of track wheels facing opposing outer directions from the top drive, each wheel defining a hub, an inner ridge, a middle ridge and an outer ridge, the ridges positioned on the outer margins of the guide tracks,  FIG. 9 . This three ridge track wheels allow for a transition between the guide tracks of the lower mast when transferring position to the upper mast. 
     II. SUMMARY OF THE INVENTION 
     A variety of forces bear upon drilling rigs in the field. As demand increase, drilling rigs are called upon to drill wells deeper to locate product, faster because of the rapid demand of consumers and refineries, and due to the increased use of horizontal drilling techniques, longer than was once used for vertical drilling operations. Because of these demands, drilling rigs are using more powerful drilling equipment which generate increasingly greater amounts of torque forces, down hole forces and drilling head speeds, which enable the drilling rig to drill faster, deeper and longer. 
     As indicated previously, modern drilling rigs are also improving in safety to those working around the drilling rigs. The oilfields are moving away from drilling rigs that have the antiquated rotary floors and moving in a direction of drilling rigs that have little direct exposure of working and deck hands to the drilling equipment. Drilling rigs and equipment are increasingly hands-free and operated by a drilling operator in a control shack on the rig which uses automated machinery to conduct a large amount of the drilling operations that used to require a human presence and pose a danger to human safety. While not without risk, the dangers are being addressed and minimized. In order to increase safety and secure a drilling rig to operate as safe a possible while delivering as much stability to the increased forces being applied to the more powerful drilling rigs, the drilling rigs are requiring more stabilization to the pivotal drilling rigs, the trailer upon which the pivotal rigs are set and the elevated platform which are attached to the pivotal drilling rigs in the elevated vertical position, improvements to the support structures of the drilling rig are the objective of the improvements being addressed in the present drilling derrick and apparatus base assembly. 
     The primary objective of the invention is to provide a secure base comprising an A-frame support structure to the lower mast of a pivotal derrick assembly in an elevated vertical position, the A-frame support structure supported by a lower member strut which is applied between the trailer floor and the lower foot of the A-frame support structure which extends from the lower mast on the rig side of the pivotal derrick assembly, as one portion of the lower support improvement. A secondary attachment is applied to the well side of the lower mast of the pivotal derrick assembly securing the well side of the elevated pivotal derrick assembly upon the deck of an elevated drilling platform which is erected on the well side of the pivotal derrick assembly,  FIG. 10 . A secondary objective of the improved portable drilling apparatus lies in the rear base frame member mounted upon the trailer bed providing a high substructure to support the pivotally attaching lower derrick mast, with the lower derrick mast, upper derrick mast, crown pulley assembly and all other attached accessories being provided with a lower transport height, the overall height along the trailer in the transport position not significantly greater than the height of the rear base frame member and the lower derrick mast. This is possible due to the A-frame support being on the rear legs and actually pivoting between the upper end of the rear base frame member and the trailer bed, the A-frame support stanchion being retracted out of the way until needed for vertical support during erection or being retracted during the takedown of the portable drilling apparatus, as demonstrated in the drawing  FIGS. 1 ,  2 ,  5 ,  6  and  12 . 
     The drilling rig which is the subject of the disclosed improvements is generally present as a pivotal drilling rig attached to a heavy duty trailer, with a cabling system located upon the trailer near a front end and the pivotal drilling rig attached to the rear end of the trailer, the trailer being further connected to a power plant to supply electrical and hydraulic power to operated the drilling rig and its related equipment, which includes operation of the hydraulic rams used to raise and lower the pivotal derrick, to raise and lower an upper mast from within a lower mast on the telescopic drilling rigs, and to power the cable systems used to raise and lower a top drive along the extended drilling rig from the crown located on the top of the drilling rig. The top drive is the location where the drilling liquids and introduced and withdrawn during the drilling operation and it is also the location where the drill stem attached to the drill head is rotated under force. The disclosed improvements, while possible being adaptable to other drilling rigs, is not necessarily applicable within this disclosure. 
    
    
     
       III. DESCRIPTION OF THE DRAWINGS 
       The following drawings are submitted with this utility patent application. 
         FIG. 1  is a side view of an improved portable drilling apparatus on a trailer with the improved portable drilling apparatus in a horizontal transport position. 
         FIG. 2  is the improved portable drilling apparatus on the trailer in the vertical operational position in operational relationship to an extendable platform assembly, shown by phantom lines. 
         FIG. 3  is an upper perspective view of an embodiment of an extendable platform base to be used with the improved portable drilling apparatus, with phantom lines indicating secondary support elements. 
         FIG. 4  is a side view of the extendable platform base with phantom lines indicating secondary support elements. 
         FIG. 5  is a rear view of a rear base frame member of the improved portable drilling apparatus. 
         FIG. 6  is a side view of the rear base frame member of the improved portable drilling apparatus, with a phantom line representation of the A-frame support stanchion in a lowered position. 
         FIG. 7A  is a well side view of a lower derrick mast within the improved portable drilling apparatus. 
         FIG. 7B  is a lateral side view of the lower derrick mast. 
         FIG. 8A  is a well side view of an upper derrick mast within the improved portable drilling apparatus. 
         FIG. 8B  is a lateral side view of the upper derrick mast. 
         FIG. 9A  is a sectional view along lines  9 A/ 9 A of  FIG. 2 . 
         FIG. 9B  is a sectional view along lines  9 B/ 9 B of  FIG. 2 . 
         FIG. 9C  is a sectional view along lines  9 C/ 9 C of  FIG. 2 . 
         FIG. 10  is an isolated view of an adjustable component on the lower end of a front leg of the lower derrick mast and its relative attachment to a secure attaching means on an upper surface of the extendable platform deck of the extendable platform assembly. 
         FIG. 11  is a top view of a crown pulley assembly utilized within the improved portable drilling apparatus. 
         FIG. 12  is an isolated view of the upper derrick mast and lower derrick mast with at least one secondary hydraulic ram to raise and lower the upper derrick mast within the lower derrick mast and one primary hydraulic ram to raise and lower the lower mast. 
         FIG. 13  is a top view of the  FIG. 9B  which includes a top drive assembly as utilized within the improved portable drilling apparatus. 
         FIG. 14  is a top sectional view of a guide track of the top drive assembly for use within the improved portable drilling apparatus. 
     
    
    
     IV. DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An improved portable drilling apparatus  10  for the drilling of a vertical or horizontal oil or gas well using a vertical derrick with a top drive drilling and fluid assembly mounted upon a flat bed trailer  400  defining a trailer bed  402  supported by a trailer frame  404  and a flat profile rear end  405 , the trailer frame supporting a cabling system and accessing an external electrical power plant and an external hydraulic pressure generating system for the erection and operation of the portable drilling apparatus  10 , the improved portable drilling apparatus  10 , demonstrated in  FIGS. 1-14  of the drawings, comprising an improved rear base frame member  20  defining a pair of vertical rear support columns  22  with an upper end  23  providing an upper plate  24  and a pivotal mounting flange  25 , a lower derrick mast  30  pivotally attached to the pivotal mounting flange  25  by a pin  36 , the lower derrick mast  30  defining a pair of parallel rear legs  32  attached together with secondary support members  40  and a pair of shorter parallel front legs  50  attached by secondary support members  40  to each respective rear leg  32 , with the area between each front leg open wherein the front legs  50  and rear legs  32  defining a channel  62 , and a pair of diagonal A-frame support members  70  attached to each rear leg  32  extending away from each front leg  50 , each diagonal A-frame support member  70  having a lower end  74 , at least one primary hydraulic ram  100  attached between the lower derrick mast  30  and the trailer frame  404  to elevate and lower the lower derrick mast  30  from a horizontal transport position,  FIGS. 1 and 12 , to a vertical operational position  FIG. 2 , a pair of A-frame support stanchions  78  pivotally attached to the trailer frame  404  which may be raised into a support position below each lower end  74  of each respective diagonal A-frame support member  70  to lock the lower derrick mast  30  into the vertical operational position, and an upper derrick mast  130  slidably engaged within the channel  62  of the lower derrick mast  30 , the upper derrick mast  130  defining two parallel rear legs  132  attached together by secondary support members  140 , and a pair of front legs  150  of equal length to the rear legs  132 , each front leg  150  attached to a respective rear leg  132  by additional secondary support members  140  with the space between the pair of front legs  150  open, wherein the rear legs  132  and front legs  150  of the upper derrick mast  130  also form a channel  162 , the improved portable drilling apparatus  10  used in conjunction with an improved extendable drilling platform assembly  500 . 
     One of the most significant improvements to pivotal and portable derricks in the prior art lies in the presentation of the present improved portable drilling apparatus  10  having a low transport height provided by a higher substructure within the rear base frame member  20  and the pivotally attached lower derrick mast  30 . This significantly increases the option of transporting the improved portable drilling apparatus upon public roadways due to the lower transport height without as much concern as being able to travel under most bridges and underpasses. As shown in  FIG. 1 , the overall transport height of the apparatus in the transport position is generally the height of the front legs  50  of the lower derrick mast  30 . This is due to two present improvements, the first being the A-frame support member  70  being attached to the rear legs  32  of the lower derrick mast  30  which pivot over the top of the retracted A-frame support stanchion  78  during erection or takedown of the drilling apparatus,  FIG. 6  shown in phantom line, with the A-frame support stanchion  78  extended,  FIGS. 2 ,  6  and  12 , to maintain the vertical erection and support to the drilling apparatus upon the trailer. The second improvement contributing to this lower transport height is the provision of the rear base frame member  20  providing a higher substructure with a smaller profile lower derrick mast  30 , profile defining the distance between the front legs  50  and rear legs  32 , and other components, reducing the overall transport height of the drilling apparatus,  FIG. 1 . As an even further improvement is the provision of the lower derrick mast  30  on the rear end  405  of the trailer  400  with shorter front legs  50  than the longer rear legs  32  with the intention of utilizing the improved portable drilling apparatus  10  with the extendable platform assembly  500 , the front legs  50  being further attached to the secure attaching means  530  on the platform deck  520 . Therefore, the lower derrick mast  30  utilizes the extendable platform deck  520  of the elevated platform assembly  500  setting upon solid ground to further support and secure the well side portion C of the portable drilling apparatus  10  instead of relying solely upon the trailer frame  404  for the entire support of the drilling apparatus  10 , support for the drilling apparatus in the vertical operational position being distributed among primarily the rear legs  32  secured upon the rear base frame member  20  upon the trailer frame  404 , secondarily by the A-frame support member  70  being held upward by the A-frame support stanchion  78  against the trailer frame  404 , and thirdly, by the front legs  50  secured upon the raised extendable platform deck  520 . 
     The improved rear base frame member  20 ,  FIGS. 5 and 6 , further defines each rear support column  22  having a base end  26  attached to the trailer frame  404  at the rear end  405  of the trailer  400 , the upper end  23  defining the upper plate  24  and pivotal mounting flange  25 , a diagonal support member  27  attached between each support column  22  and the trailer frame  404  and an upper cross member  28  welded between each upper end  23  of each support column  22 . 
     The lower derrick mast  30 ,  FIGS. 7A and 7B , further defines the two rear legs  32 , two front legs  50  and secondary structural components  40  which support the rear legs  32  and front legs  50  forming a rectangular profile frame  60 ,  FIG. 9A , defining a rig side portion B behind the rear legs  32 , a well side portion C in front of the front legs  50  and two lateral side portions D between each adjacent front leg  50  and rear leg  32 , with the well side portion C being the location for a channel opening  64  to the channel  62 , the two rear legs  32  further defining a lower end  33  attaching a lower plate  34  and a lower extending pivotal mounting flange  35  engaging the respective aligned pivotal mounting flange  25  upon each rear support column  20  by a bolt or the pin  36 , providing the lower derrick mast  30  pivotally engaged with the rear base frame member  20 , the rear legs  32  being spaced apart the same distance as the support columns  22  wherein the upper plate  24  of the support columns provide support to the respective lower plates  34  on each rear leg  32  of the lower derrick mast  30  when the lower derrick mast  30  is in the elevated vertical operational position. 
     Each A-frame support member  70  extending behind from the lower derrick mast  30  opposite the front legs  50 ,  FIGS. 2 and 7B , further defines an upper end  72  welded to the respective rear leg  30  and a lower end  74  defining a lower foot plate  75  terminating at an even horizontal level with the lower end  33  and lower plate  34  of the rear leg  32  with various secondary support members  76  attached between each A-frame support member  70  and the respective lower leg  32  of the lower derrick mast  30  with the pair of A-frame support stanchions  78  pivotally attached to the trailer frame  404  elevating upward from the trailer frame  404  and locking into a vertical position below the respective lower foot plates  75  of each A-frame support  70  to provide additional locking support to the lower derrick mast  30  in the elevated vertical operational position. 
     The upper derrick mast  130  defining two rear legs  132 , two front legs  150  and various secondary support members  140  which support the rear legs  132 ,  FIGS. 8A and 8B , also form a rectangular profile frame  160 ,  FIG. 9C , also defining a rig side portion B behind the rear legs  132 , a well side portion C in front of the front legs  150  and two lateral side portions D between each adjacent front leg  150  and rear leg  132 , the front legs  150  defining a channel opening  164  on the well side C of the channel  162 , the rectangular profile frame  160  of upper derrick mast  130  being smaller in diameter than the rectangular profile frame  60  of the lower derrick mast  30  wherein the upper derrick mast  130  is slidably engaged within the lower derrick mast  30  in a telescoping manner with the open channels  32 ,  162  of the upper and lower derrick masts both being open towards the rig side B,  FIG. 9B , the upper derrick mast  130  being raised and lowered by at least one secondary hydraulic ram  170 ,  FIG. 12 , provided within the channel  62  between a lower end  166  of the upper derrick mast  130  and the lower derrick mast  30  forcing the upper derrick mast  130  from within the channel  62  of the lower derrick mast  30  and extending an upper end  168  of the upper derrick mast  130  above the lower derrick mast  30  while in the raised vertical operational position. The upper derrick mast  130  further defines the upper end  168  supporting a crown pulley assembly  200  comprising a frame  205  and a series of cable pulleys  210  through which a cable is utilized to raise and lower a top drive assembly  300  with the channels  62 ,  162  of the upper and lower derrick masts  30 ,  130  during drilling operations performed by the improved portable drilling apparatus  10 . 
     It is preferred that the improved portable drilling apparatus  10  be utilized in conjunction with an extendable elevating platform assembly  500 ,  FIGS. 3 and 4 , constituting a further improvement to the support and operation of the drilling apparatus, the platform assembly  500  providing a trailer support plate  510  securing to an extendable platform deck  520 ,  FIGS. 2 and 3 , forming a T-shaped support base  515 , the trailer support plate  510  lying flat upon the prepared ground surface, and providing the flat and level support structure upon which the portable drilling apparatus  10  is set throughout the entire drilling, completion and other operations of the portable drilling apparatus  10  and operational apparatus are conducted. The extendable platform deck  500  further is set with the rear end  405  of the trailer  400 ,  FIG. 2 , upon which the improved portable drilling apparatus  10  is secured, the rear end  405  aligned below the adjacent extendable platform deck  520 , the deck further defining an upper surface  525  having a secure attaching means  530  for the secure attachment of a lower end  51  of the front legs  50  of the lower derrick mast  30  resting thereon,  FIG. 10 , which further stabilizes the trailer  400  and portable drilling apparatus  10  during drilling operations by locking the front legs  50  into position upon the platform deck  520 . This extendable elevating platform assembly  500  reduces the need to stabilize the surface underneath the trailer  400  and derrick assembly  10  once the trailer support plate is  510  placed upon the prepared level and stable ground surface. These components and their orientation are shown in  FIGS. 2-4  and  12 . 
     The extendable platform deck  520  further comprises four extending hydraulic support members  540  which elevate the extendable platform deck  520  into a raised operational position,  FIG. 2 , and lowered into a transport position, by a hydraulic means. The elevated platform deck  520 , providing several necessary openings, accessory structures and components required for the drilling and completion of a well, is extended to a height above the ground of approximately fifteen feet, which is a generous height under which equipment and material can be supplied below the elevated platform, with protection underneath to those involved in the operation from the overhead activity. It also provides ample space for the completion process which often requires the placement of heavy valves and pipes using heavy construction equipment for the recovery of the product withdrawn from the well. The T-shaped support base  515  increases the distribution of forces generated by the derrick assembly  10  during operation, assembly and removal. As indicated before, it also provides a stable mounting surface for an operational and control enclosure  550  and the very few workers required to conduct operations, which the improved portable drilling apparatus and the extendable elevating platform assembly reducing the exposure of employees to the platform deck during drilling operations, most activity being controlled by a single operator in the control enclosure. The platform assembly would further provides the operational and control enclosure with a detachable staircase for an operator to ascend into the control enclosure from the ground with the operational and control enclosure situated in a position where the drilling operation can be viewed during operations. 
     In addition to the disclosed features of the trailer  400 , the rear base frame member  20 , and the telescoping lower and upper derrick masts  30 ,  160 , the improved portable drilling apparatus further comprises the crown pulley assembly  200  located at the upper end  168  of the upper derrick mast  130 , as indicated in  FIGS. 1 ,  2  and  11 , which is used in conjunction with a single cable attached to the cabling system located on the trailer. The cabling system, the cable and the crown pulley assembly  200  are used during the drilling operation to raise and lower a standard or an improved top drive assembly  300  with the portable drilling apparatus  10 , the improved top drive assembly  300  integrated with the upper and lower derrick masts  30 ,  130  within the channels  62 ,  162 , and raised and lowered within the channels by the cable over the series of pulleys  210  within the crown pulley assembly  200 , controlled by the cabling system by the operator within the control enclosure. 
     The improved top drive assembly  200 ,  FIG. 13 , while more specifically disclosed and claimed under separate patent, provides the top drive  200  with opposing lateral dual channel guide tracks  310  which are guided along singular guide rails  54 ,  154 , each guide rail  54 ,  154 , having a rear surface  55 ,  155 , attached upon respective inner facing surfaces  52 ,  152 , of the front legs  50 ,  150 , of the upper and lower derrick masts  30 ,  130 , within the channel  62 ,  162 , the guide rails  54 ,  154 , of the lower derrick mast  30  and upper derrick mast  130  being aligned parallel, with a section of the guide rails of the lower derrick mast and the upper derrick mast overlapping where the upper and lower derrick masts overlap during full extension, again  FIG. 13 , the dual channel guide tracks  310  of the top drive  300  providing a secure transaction and transfer between the guide rails  54 ,  154  of the lower and upper derrick masts  30 ,  130 . The improvement over prior top drive assemblies lies within the lateral dual channel guide tracks  310 ,  FIG. 14 , defining first and second channel guide segments  312 ,  314 , aligned in parallel with a friction reducing lining  315  and also having adjustable upper and lower guide track wheels  316 ,  318 , which ride upon inner facing surfaces  56 ,  156  of the guide rails  54 ,  154 , providing a much smoother ride of the top drive assembly  300  within the channels  62 ,  162 , requiring less force to move the top drive assembly  300  up and down the channels  62 ,  162 , to improve the secure lateral stability of the top drive assembly  300 , and to reduce wear and tear of the dual channel guide tracks  310  and the guide rails  54 ,  154  during repeated use. 
     The significant operational performance capacity is realized by the improvement of the present portable drilling assembly  10  due to the enhanced support of the rear base frame member  20 , the A-frame support  70 , and the A-frame support stanchions  78 , which not only provide additional base support to the drilling apparatus but also provide the drilling apparatus with the capacity to increase the amount of drilling torque which can be applied to the drilling operations. In this regard, when the lower derrick mast  30  is elevated into the vertical drilling position by the at least one hydraulic ram  100 , the hydraulic ram  100  will provide the ability to move the lower derrick mast  30  beyond a vertical position and actually push the lower mast somewhat forward of a vertical axis A towards the well side C and the extendable platform assembly  500 . Once the lower derrick mast  30  is extended, the A-frame support stanchions  78  are put into position below the lower foot plates  75  of the A-frame support members  70  to maintain this forward projection of the lower and upper derrick masts  30 ,  130 , during drilling operations with at least 60% of the weight of the drilling assembly  10  on the well side C, further held in position by the attachment of the lower end  51  of the front legs  50  to the secure attaching means  530  on the upper surface  525  of the extendable platform deck  520 , which involves some preferred adjustable components  53  for final positioning of the lower derrick mast  30  to a preferred stable position prior to the commencement of drilling operations in conjunction with the stabilization of the lower foot plate  75  of the lower end  74  of each A-frame support  70  by the placement of each A-frame support stanchion  78  below each lower foot plate  75 . 
     One of the most significant improvements to pivotal and portable derricks in the prior art lies in the presentation of the present improved portable drilling apparatus  10  having a low transport height provided by a higher substructure within the rear base frame member  20  and the pivotally attached lower derrick mast  30 . This significantly increases the option of transporting the improved portable drilling apparatus upon public roadways due to the lower transport height without as much concern as being able to travel under most bridges and underpasses. As shown in  FIG. 1 , the overall transport height of the apparatus in the transport position is generally the height of the front legs  50  of the lower derrick mast  30 . This is due to two present improvements, the first being the A-frame support member  70  being attached to the rear legs  32  of the lower derrick mast  30  which pivot over the top of the retracted A-frame support stanchion  78  during erection or takedown of the drilling apparatus,  FIG. 6  shown in phantom line, with the A-frame support stanchion  78  extended,  FIGS. 2 ,  6  and  12 , to maintain the vertical erection and support to the drilling apparatus upon the trailer. The second improvement contributing to this lower transport height is the provision of the rear base frame member  20  providing a higher substructure with a smaller profile lower derrick mast  30 , profile defining the distance between the front legs  50  and rear legs  32 , and other components, reducing the overall transport height of the drilling apparatus,  FIG. 1 . As an even further improvement is the provision of the lower derrick mast  30  on the rear end  405  of the trailer  400  with shorter front legs  50  than the longer rear legs  32  with the intention of utilizing the improved portable drilling apparatus  10  with the extendable platform assembly  500 , the front legs  50  being further attached to the secure attaching means  530  on the platform deck  520 . Therefore, the lower derrick mast  30  utilizes the extendable platform deck  520  of the elevated platform assembly  500  setting upon solid ground to further support and secure the well side portion C of the portable drilling apparatus  10  instead of relying solely upon the trailer frame  404  for the entire support of the drilling apparatus  10 , support for the drilling apparatus in the vertical operational position being distributed among primarily the rear legs  32  secured upon the rear base frame member  20  upon the trailer frame  404 , secondarily by the A-frame support member  70  being held upward by the A-frame support stanchion  78  against the trailer frame  404 , and thirdly, by the front legs  50  secured upon the stationary extendable platform assembly  500 . 
     While the improved portable drilling apparatus  10  has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that changes in form and detail may be made therein without departing from the spirit and scope of the improvements to the portable drilling apparatus  10 .