Abstract:
A well control valve assembly having a downhole portion with a primary valve, and electromechanical actuator connected to the valve and a first wireless communicator connected to the actuator. The assembly further includes an uphole portion having a pump, a second wireless communicator complementary to the first wireless communicator and being supported in the uphole portion of the valve assembly. The downhole portion and uphole portion are physically non-connected and informationally connected.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of an earlier filing date from U.S. Provisional Application Ser. No. 60/207,756 filed May 30, 2000 which is fully incorporated herein by reference. 
    
    
     BACKGROUND 
     THE PRIOR ART 
     In certain wells that naturally produce very slowly, pumps are desirable. Pumps can increase the rate of production by pumping fluid faster than the well could otherwise push the fluid. Pumps, therefore, are desirable in many well situations. A drawback of the use of pumps however is that they generally have a limited life span (pumps generally have a life of about 80% shorter than other well components). Limited life span components necessitates frequent repair or replacement. In order to repair or replace a pump it must be withdrawn from the well. The activity requires that the well be opened. Thus, unless there is a means to close off the well or the well is killed dead, the removal of the pump causes spillage of well fluid into the surrounding environment. Clearly, this occurrence is environmentally unsound. To prevent said spillage, various attempts have been made to actuate a valve beneath the pump. 
     One prior art method employs a sleeve valve under the pump which is shiftable by a shifting sub. The sub includes an elongated section having a shifting profile thereon that engages a sleeve, through profile receptacles, shifts the same and then disengages therefrom in the downhole direction. The length of the shifting sub and all of the pipe joints thereabove must be exactly the same each time the upper section is pulled and run back in the hole or the sleeve will be damaged. Damage is caused by things being smashed into each other due to different lengths. Certainty about whether or not the sleeve is closed is also lacking. 
     Another prior art method for controlling flow when the pump is removed and, thus, the well is open is to employ a ball choke below the pump. The device operates on 50 to 200 psi and upon such pressure causes the valve to cycle in a “J” groove between on and off positions. The valve contains a ball receptacle which contains a “J” groove well known in the art, to cycle the valve to alternating on/off positions. The groove feature is actuated by pressurizing the well from the surface. Although the valve does function correctly in controlled conditions, the confidence in the positioning of the valve in the field is low. It is very difficult to definitively determine that the valve has been cycled only once when the pressure inducing apparatus is large. Because the valve is actuated between 50 and 200 psi and then bleeds pressure past the ball it is extremely easy to double cycle the valve which leaves it open again. Because of the lack of confidence in the position of the valve, delay is experienced. The well operator must wait a period of time after an attempted cycling to see if pressure climbs within the well or does not. This is the only assurance of the condition of the valve. If pressure does not rise, the valve is closed, if pressure does rise, the valve is open. Since, of course, in the oil production industry time is tremendously expensive, the method leaves much to be desired. 
     A system having a pump which can be separately removed from the well while leaving the valving structure intact and wherein such a system is reliable and in communication with other well functions. 
     SUMMARY 
     The above-discussed and other problems and deficiencies of the prior art are overcome or alleviated by the production well control system of the present disclosure. 
     The disclosure solves the problems inherent in the prior art and additionally provides optimization of well production. 
     In the disclosure, the pump is mechanically separated both from the valve structure and from valve operation such that the removal of the pump for repair or replacement may be accomplished without removal of or any deleterious effect on the valve system. Since, of course, communication is required between the pump and valve system and is desirable even beyond the valve system, a hydrophone or geophone is employed on each portion of the pump and valve system of the disclosure to provide communication across the mechanical gap between the pump assembly and the valve assembly. The first concept of the disclosure is sufficient to enhance the state of the art for pump repair and replacement. The disclosure however includes an additional and important feature. 
     In the additional feature of the disclosure, the valve assembly includes both primary and secondary valve structures, the primary valve being actuatable selectively, preferably by a downhole intelligence package, and the secondary valve structure being actuatable by removal or insertion of the primary valve structure. Because of the sensor(s) and controller involved with actuation of the primary valve, the system of the disclosure provides not only an on/off valve for pump issues but, further provides optimization of production of the well by enabling the valve to sense certain parameters regarding production and tailor the valve opening to produce the well as efficiently as the particular formation will allow. The information gained and decision made by the controller can also, of course, be transmitted to other locations by the hydrophone/geophone link or by wireline. The information is then also employed to modify pump rate to match the well production capability. 
     The above-discussed and other features and advantages of the present disclosure will be appreciated by and understood by those skilled in the art from the following detailed description and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic elevation view of the monitoring and drawdown optimization system; and 
     FIG. 2 is an enlarged view of the circumscribed area  2 — 2  in FIG.  1  and illustrates the actuation mechanism of the secondary valve of the system. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present disclosure provides for selective optimization and draw down of fluid flow through the borehole in which the system is installed while facilitating repair of more easily expended tools without disruption of other tools or uncontrolled flow from the well. The drawdown characteristic of the system is discussed first and its ability to optimize well production is discussed thereafter. 
     Referring to FIG. 1, the system is schematically illustrated. The system comprises two major, mechanically independent components. A downhole portion  102  is supported by packer  110  set in a wellbore  106  whereas the uphole portion  104  is supported by tubing  152 . The mechanically independent nature of the major parts of the system achieves the objective regarding the pulling of the pump with an effect wholly independent of the valve structure residing downhole thereof. In the system, virtually all of the components that have the longer service life are separated from the pump. When the pump is to be pulled from the well a signal need merely be sent to the valve structure to close the same and then the pump may be pulled. The valve may even automatically open and close based upon the acoustic signature of the pump. The valving components of the system need only be pulled when they themselves require repair or replacement. 
     The downhole portion  102  of the system, which comprises the valve structure and electronics, is supported by the packer  110  which acts as a platform to locate portion  102 . Portion  102  comprises housing  112  which supports secondary valve body  114  therein. Secondary valve body  114  is a mechanically actuated valve openable upon the engagement therewith of a primary sleeve valve  118  and closeable upon withdrawal of the primary valve from engagement therewith. Valve  118  engages body  114  at collet interface  116  (See FIG.  2 ). The mechanical action of engaging primary sleeve valve  118  through collet sub  115  and collet  116  to body  114  itself causes an inner sleeve  120  to move downhole and open a series of ports composed of sleeve ports  124  aligned with housing ports  122 . When primary sleeve valve  118  lands on sleeve  120 , the sleeve is urged down hole an amount sufficient to align ports  124  with ports  122 . The purpose of secondary valve body  114  is to prevent flow past the housing  112  in the event the primary sleeve valve  118  is removed from the engaged position. Secondary valve body  114  is closed during removal of primary valve  118 . Flow through secondary valve body  114  is allowed only while primary sleeve valve  118  is in its proper position. As one of skill in the art will appreciate then, the regulation of flow through portion  102  is primarily the responsibility of primary sleeve valve  118 . 
     Referring again to FIG. 2, primary sleeve valve  118  is connected to sleeve  120 , as stated, by collet  116 . Collet  116  is of a type known to the art and provides several deflectable fingers  117 . Initially, upon movement of primary sleeve valve  118  uphole, the collet (part of sleeve  120 ) is drawn uphole, closing ports  122 . When the secondary valve body  114  is completely closed, fingers  117  move into recess profile  119  in housing  112 . Recess profile  119  allows fingers  117  to deflect sufficiently to disengage from valve  118  that it may be removed. Thereafter recess profile  119  acts as a detent groove to hold secondary valve  114  closed. The reverse takes place upon installation of primary valve  118 . Once valve  118  is engaged with fingers  117  it continues in the downhole direction until it abuts land  121  and forces body  114  downhole to align ports  122  and  124 . Three seals  123  exist on each valve body and preferably are chevron seals. A housing port may be aligned with a valve body port when seals  123   a  and  b  straddle the port and is misaligned with the valve body port when seals  123   b  and  c  straddle the housing port. The seals prevent leakage around the respective valve bodies. 
     Primary valve  118  when installed in the well is controlled electromechanically by an electronics/control package  128  which is connected at interface  130  mechanically and electrically to primary valve  118 . The electronics/control package  128  preferably contains a power source (e.g. battery pack, generator, capacitor, etc.)  132 ; a sensor  134  which may be a temperature, pressure, flow rate, water/oil ratio, vibration, particle motion or other parameter or a combination sensor; (more than one sensor could be employed in and around the valve assembly for example at least two sensors disposed above and below said primary valve with the below valve sensor schematically shown at  134   a ); a PC board  135 ; and an electro-mechanical valve actuator  136 . 
     Any type of electromechanical actuator is contemplated including a motor and gear set, a solenoid, magnetic actuation, etc. Finally an electronics package receptacle  140  is attached to primary sleeve valve  118 . This receptacle assists in positioning control package  128 . It should also be noted that package  128  includes hydrophone  158  which is required for functionality of this embodiment, and nipple  142 . The nipple is engageable by a conventional retrieval tool. Thus, in the event that downhole portion  102  must be pulled from the hole this can be easily accomplished with existing hardware. Control package  128  also provides in-well adjustability for the valve including adjustments of opening closing pressures in the well in real time. 
     The upper portion  104  of the system includes electric submersible pump  150  mounted to string  152  and a hydrophone (or geophone)  154  fed by a hard wire  156  to the surface or to another downhole location as desired. Since hydrophone  154  is preferably wired to the surface, information can clearly be transmitted thereto and received therefrom. Hydrophone  154  is capable of communicating acoustically with hydrophone  158  thereby maintaining communication in the form of transmission and reception of information between the surface or other downhole controllers and downhole portion  102  of the system. The hydrophones provide all necessary communication for the embodiment and enable the no-mechanical-connection system to be operable. The information transmittable between the hydrophones enables control of the condition (degree of openness) of valve  118  from a surface or downhole control location. For safety reasons a pressure sensitive closure of the valve  118  is preferred. More specifically, the valve closes automatically when down hole and requires a signal to open. This ensures that the valve  118  will stay closed when initially run until it receives a signal to open. It also is a fail-safe feature since without the open signal from hydrophone  154 , primary sleeve valve  118  will shut-in the borehole. 
     Beyond the benefit the system has in overcoming the deficiencies of the prior art the consideration of which led to its conception, the system provides another benefit never even attempted before. As one of skill in the art will recognize a very simple controller can do the job of package  128  to discharge the duties of the system with respect to its intended purpose of allowing withdrawal of the pump for replacement or repair while maintaining control of the well. The present inventor recognized another benefit of a system such as this however if more intelligence could be imparted to package  128 . Thus the sensors and electronics as discussed were developed to allow the system to monitor the head of fluid above the pump, whether the head grows or declines and other factors. By so measuring the primary valve  118  is settable through command by the controller  128  or by surface control (command received through hydrophones  158  and  154 ) to throttle the expressed formation fluids to maintain a steady and appropriate head above the pump. This condition optimizes production from the formation by effectively producing as much hydrocarbonaceous fluid as the well will bear. By maintaining the head and monitoring any movement the pump can be protected from premature failure due to running dry. Since the sensing devices and communications capabilities are in the immediate vicinity of the pump, the pump can be shut down before any harm results due to insufficient oil available to the pump. It is a significant benefit to the industry to provide an optimization system which is also a drawdown system. The environment is spared oil spillage and well operators are spared cost. Another aspect of this embodiment is that pump  150  is preferably mounted with its motor more downhole than its intake opening(s). The purpose of this is to enhance cooling of the motor from the movement of wellbore fluids over the motor. Such cooling action on the motor may prolong the service life thereof. 
     In an alternate embodiment, the open command may be the acoustic signature of the motor itself. Thus, an open signal need not be sent from the surface or other downhole command location and yet the well operator will be assured that the primary valve is open when the pump is on and closed when the pump is off. A benefit of the arrangement is that it avoids premature pump failure due to pumping when the valve is closed. 
     While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.