Abstract:
A method for removing sludge from a crude oil storage tank comprising a bottom and a moveable roof configured to float on the top of a quantity of crude oil disposed in said storage tank, where the method includes reducing a volume of crude oil in the storage tank to about a level of a sludge sediment in the storage tank, measuring a topology of the sludge disposed on said bottom, reliquefying asphaltene deposits, pumping the reliquefying asphaltene deposits out of the storage tank, wherein the method is performed without the entry of one or more persons into said storage tank.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This Application claims priority to a U.S. Provisional Application filed Jul. 24, 2012, and having Ser. No. 61/675,287, which is hereby incorporated by reference. 
     
    
     FIELD 
       [0002]    Embodiments generally relate to tank cleaning and more particularly to compositions of matter, articles of manufacture, methods, devices, and systems for non-entry hydrocarbon tank cleaning. 
       BACKGROUND 
       [0003]    High molecular weight organic sediments deposit in tanks that store crude oil. These deposits form sludge, which reduces the storage capacity of the tank. Industry maintenance of such tanks requires their frequent cleaning, which imposes risks to the cleaning crew and the environment, and renders the tank inoperable for a period of time. The potential hazards for man entry systems include mortal harm to the cleaning crew due to chemical exposure, asphyxia, and risk of combustion of the tank content. For example, electrostatic charges originating from spray mists or body movements (electrostatic charges from rubbing of clothing) has the potential to ignite the content of the tank leading to a dangerous explosion. Moreover, the disposed sludge often includes oil, which results in cargo loss, amounting to a shortfall in usable oil and revenue. 
         [0004]    Accordingly, it would be an advance in the art to provide solutions that can address the above challenges. 
       SUMMARY 
       [0005]    In certain embodiments, a desludging storage tank includes a tank body and a fluid injection device. The fluid injection device includes an outlet end directed into the tank body and an opposite, inlet end coupled to a source of fluid that includes diesel. In certain embodiments, a method for desludging a storage tank includes reducing a volume of crude oil in the storage tank to about a level of a sludge sediment in the storage tank. A topology of the sludge sediments on a first inner surface of the storage tank is measured. An additive and diesel are injected into the storage tank. A heating coil heats the sludge sediment. Nitrogen is injected into the storage tank. The liquefied sludge sediments are pumped out of the storage tank. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The invention will be better understood from a reading of the following detailed description taken in conjunction with the drawings in which like reference designators are used to designate like elements, and in which: 
           [0007]      FIG. 1  is a schematic of an exemplary storage tank; 
           [0008]      FIG. 2  is a schematic showing a top, cross-sectional view of a desludging storage tank; 
           [0009]      FIG. 3  is a schematic showing a side view of the desludging storage tank of  FIG. 2 , wherein the shell and the roof of the desludging storage tank is transparent to illustrate the internal components of the desludging storage tank; 
           [0010]      FIG. 4  illustrates Applicants&#39; crude oil storage tank in combination with a plurality of computer-operated valves; and 
           [0011]      FIG. 5  is a flow chart of an exemplary method for non-entry tank cleaning 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    The invention is described in preferred embodiments in the following description with reference to the FIGs., in which like numbers represent the same or similar elements. Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” “in certain embodiments,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. It is noted that, as used in this description, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. 
         [0013]    The described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are recited to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. 
         [0014]    Sludge and gels are produced by the gradual sedimentation of heavy oil fractions in a storage tank. Sludge is an emulsion, varying in thickness, consistency, density, and composition across the storage tank bottom. These sediments are typically a stable, multiphase solid/oil/water product, that is in a semisolid physical state. Inorganic solids in the crude oil, (e.g., clay, calcite, silica, and corrosion-produced residues) bring more hardness and increase density to the sludge. During storage, accumulating sediment compacts with organic compound degradation that produces a thick layer of sludge deposits at the bottom of the tank, which is difficult to remove. 
         [0015]    Referring to  FIG. 1 , a crude oil storage tank  100  is illustrated. The storage tank  100  body stores crude oil, for example, and includes at least one side  102  coupled to a bottom  106 . Here, the side of the storage tank  100  body is shown as a cylindrical shell  104  that is coupled to a circular bottom. Other configurations are also contemplated, such as a polygon configuration, spherical configuration, and the like. Storage tank  100  has a large volume capacity. In certain embodiments, the volume capacity of the storage tank  100  is within a range of 5,000-10,000 Metric Tons of crude oil, with a cross-sectional diameter of about 75 meters or more. In certain embodiments, the storage tank  100  body, and other tank bodies disclosed herein, are made of metal, such as steel, that has a corrosion resistive coating with a cathodic protection system. 
         [0016]    Storage tanks that hold fluid have fixed or floating roofs based on the intended functionality and/or the flash-point of the substance contained in the storage tank. In  FIG. 1 , the storage tank  100  is illustrated as having a floating roof  106  that is configured to rise or fall with the level of the content inside the storage tank  100 , which decreases the vapor space above the liquid level. The storage tank  100  of  FIG. 1  includes means for personnel access. Stairs  110  lead up to the floating roof  106  and a manhole  108  is disposed on the floating roof  106 . The tank  100  further includes an outlet shown as a drain valve  118  for draining the content of the storage tank  100  and a filling inlet  116  for filling the storage tank  100 . In certain embodiments, an externally accessible thermometer  114  allows for detection of the temperature of the content in the storage tank  100 . 
         [0017]    Use of a desludging storage tank allows for about 80-100% full crude value recovery. A desludging storage tank includes an additive for a thremochemical treatment of oil sludge. The additive reliquefies sludge or residual oil, such as waxy (paraffinic) or asphaltene deposits. The additive is a powerful emulsion breaker that de-stabilizes emulsions. In certain embodiments, the additive works in lieu of expensive surfactant as it treats the crude directly and does not dilute in the water phase as the product is hydrophobic in nature and repels aqueous solutions. 
         [0018]    In certain embodiments, the additive re-mediates petroleum based compounds such as heavy oils by replacing the lost volatile fractions with temperature resistant molecules which do not vent easily. The additive is organic in nature with no catalyst poisoning and produces a long lasting effect of creating flowable crudes without wax reformation. In certain embodiments, the additive is devoid of contaminating agents that provoke the alkalinization of the solution. 
         [0019]    In certain embodiments, Applicants&#39; additive comprises a combination of hydrocarbons obtained by treating a petroleum fraction with hydrogen in the presence of a catalyst. It consists of hydrocarbons having carbon numbers predominantly in the range of C 9  through C 16  and boiling in the range of approximately 150° C. to 290° C. (302° F. to 554° F.). 
         [0020]    In certain embodiments, Applicants&#39; additive is formed by a fractional distillation of crude oil between 200° C. (392° F.) and 350° C. (662° F.) at atmospheric pressure, resulting in a mixture of carbon chains that typically contain between 8 and 21 carbon atoms per molecule. 
         [0021]    In certain embodiments, Applicants&#39; additive comprises a hydrogenated, light petroleum distillate. In certain embodiments, Applicants&#39; additive comprises a mixture of hydrocarbon compounds, wherein that mixture is assigned Chemical Abstracts System (“CAS”) Number 64742-47-8. In certain embodiments, Applicants&#39; additive comprises a product sold in commerce under the tradename Drakesol 165. In certain embodiments, Applicants&#39; additive comprises a product sold in commerce under the tradename Drakesol 2251. In certain embodiments, Applicants&#39; additive deodorized kerosene. 
         [0022]    In certain embodiments, Applicants&#39; additive comprises a hydrogenated, medium petroleum distillate. In certain embodiments, Applicants&#39; additive comprises a mixture of hydrocarbon compounds, where that mixture is assigned CAS No. 64742-46-7. In certain embodiments, Applicants&#39; additive comprises a product sold in commerce under the tradename Drakesol 205. In certain embodiments, Applicants&#39; additive comprises a product sold in commerce under the tradename Drakesol 2257. 
         [0023]    Referring to  FIGS. 2 and 3 , a desludging storage tank  200  is depicted in a top, cross-sectional view and a side view, respectively. For illustrative purposes,  FIG. 3  shows the wall or side  201  of the desludging storage tank  200  body and roof as transparent in order to illustrate the desludging storage tank&#39;s  200  inner workings The desludging storage tank  200  body includes a wall or side  201  coupled to a bottom  224 . As stated previously, other configurations for the body of the desludging storage tank  200  are also contemplated. A floating roof  305  is configured above the bottom  224  of the desludging storage tank  200 . Here, the crude oil has been removed from the desludging storage tank  200  exposing the sludge  205  deposited at the bottom  224  of the desludging storage tank  200 . 
         [0024]    The desludging storage tank  200  includes a fluid injection device configured to inject one or more fluids, such as a first fluid from fluid reservoir  320  (e.g., a liquid reservoir) and/or a second fluid from fluid reservoir  330  and/or a third fluid from fluid reservoir  340 , into the storage tank  200 . In certain embodiments, the first fluid is the additive, the second fluid is diesel, and the third fluid is nitrogen (e.g., 62,500 m3 nitrogen from nitrogen pallets). 
         [0025]    In certain embodiments, the fluid injection device includes one or more movable, vertical lances  202 ,  206 , and  210 , each having an outlet end ( 302 ,  306 , and  310 , respectively) and an opposite, inlet end ( 304 ,  308 , and  312 , respectively). Here, the outlet end of the lances  202 ,  206 , and  210  are each coupled to a corresponding tripod to stabilize the lance. Although three lances  202 ,  206 , and  210  are shown in  FIGS. 2 and 3 , any number of lances are applicable, such as between zero and  500  lances. In certain embodiments, the lances  202 ,  206 , and  210  are mobile such that they can be configured anywhere within the tank. In  FIGS. 2 and 3 , the lances  202 ,  206 , and  210  are shown to be configured to be somewhat equal distance from one another within the tank. The lances  202 ,  206 , and  210  are coupled to the floating roof  305 . 
         [0026]    The respective inlet ends  302 ,  306 , and  310  of the lances  202 ,  206 , and  210  are each coupled to a liquid delivery system that delivers a fluid from one or more fluid reservoir  320  and/or fluid reservoir  33  and/or fluid reservoir  340 , into the desludging storage tank  200 . In  FIG. 3 , the fluid delivery system includes fluid reservoirs  320 ,  330 , and  340 , that are each coupled to one or more of the lances  202 ,  206 , and  210  via fluid manifold  410  and hosing or pipes  314 ,  316 , and  318 , respectively. Other configurations are also contemplated. In certain embodiments, the fluid reservoir  320  is coupled to a first set of lances while fluid reservoir  330  is coupled to a different, second set of lances, and the like. In certain embodiments, pumps and valves push fluid through the fluid delivery system for injection into the storage tank  200 . 
         [0027]    The respective outlet ends  304 ,  308 , and  312  of the lances  202 ,  206 , and  210  are each configured to inject the fluid(s) from the fluid delivery system into the desludging storage tank  200 . Each lance  202 ,  206 , and  210  has a respective fluid propelling capacity. The fluid propelling capacity of each lance  202 ,  206 , and  210  is a volume or spatial distance around the outlet end of the respective lance within which the fluid will be injected from the respective lance into the desludging storage tank  200 . In  FIG. 3 , the spatial distance for the lances  202 ,  206 , and  210  is illustrated as the fluid propelling capacities  204 ,  208 , and  212 , respectively. 
         [0028]    Alternatively, or in combination to having one or more lances  202 ,  206 , and  210 , in certain embodiments the fluid injection device includes injection points disposed on one or more walls  201  of the desludging storage tank  200 . In  FIGS. 2 and 3 , injection points  220 ,  226 , and  228  are depicted. Although three injection points  220 ,  226 , and  228  are depicted in  FIGS. 2 and 3 , any number of injection points are applicable, such as between zero to  500  injection points. Each injection point  220 ,  226 , and  228  has its own respective fluid propelling capacity, depicted as  230 ,  236 , and  238 , respectively, in  FIG. 2 . 
         [0029]    In certain embodiments the desludging storage tank  200  includes an agitation system which increases the pressure and flow of fluid within the desludging storage tank  200 . For example, in certain embodiments, the agitation system includes one or more impellers, agitators and/or recirculation pumps that are deposed on or within the desludging storage tank  200 . Referring to  FIG. 2 , three impellers  222 ,  214 , and  218  are disposed on the wall  201  of the desludging storage tank  200 . The impellers are made of materials such as of iron, steel, bronze, brass, aluminum or plastic, for example. Although three impellers  222 ,  214 , and  218  are illustrated in  FIG. 2 , any number of impellers are applicable, such as between zero and  500  impellers. The impellers  222 ,  214 , and  218  of  FIG. 2 , rotate accelerating the fluid within the desludging storage tank outwards from the center of rotation of the respective impeller (shown as motions  221 ,  213 , and  217 , respectively). 
         [0030]    Referring to  FIG. 3 , external fluid reservoir  320  is partially or completely filled with a first fluid  322 . In certain embodiments, first fluid  322  comprises Applicants&#39; additive. Valve  324  controls release of fluid  322  into manifold  410 . Valve  324  is interconnected with controller  400  via communication link  326 . 
         [0031]    External fluid reservoir  330  is partially or completely filled with a second fluid  332 . In certain embodiments, second fluid  332  comprises diesel fuel. Valve  334  controls release of fluid  332  into manifold  410 . Valve  334  is interconnected with controller  400  via communication link  336 . 
         [0032]    External fluid reservoir  340  is partially or completely filled with a third fluid  342 . In certain embodiments, third fluid  342  comprises nitrogen. Valve  344  controls release of fluid  342  into manifold  410 . Valve  344  is interconnected with controller  400  via communication link  346 . 
         [0033]    Valve  418  controls release of one or more fluids from manifold  410  into piping  318 . Valve  418  is interconnected with controller  400  via communication link  428 . 
         [0034]    Valve  414  controls release of one or more fluids from manifold  410  into piping  314 . Valve  414  is interconnected with controller  400  via communication link  424 . 
         [0035]    Valve  416  controls release of one or more fluids from manifold  410  into piping  316 . Valve  416  is interconnected with controller  400  via communication link  426 . 
         [0036]    Valve  413  controls release of one or more fluids from manifold  410  into fluid injection device  220  via piping  313 . Valve  413  is interconnected with controller  400  via communication link  423 . Valve  415  controls release of one or more fluids from piping  313  into fluid injection device  228  via piping  315 . Valve  415  is interconnected with controller  400  via communication link  425 . Valve  417  controls release of one or more fluids from piping  315  into fluid injection device  226  via piping  317 . Valve  417  is interconnected with controller  400  via communication link  427 . 
         [0037]    In certain embodiments, the fluid delivery system and/or the fluid injection device and/or the agitation system are controlled by a controller  400 . Referring to  FIG. 4 , a controller is illustrated as a computing device  430 . Although a single computing device  430  is depicted in  FIG. 4 , any number of computing devices is applicable to control the fluid delivery system, and/or the fluid injection device, and/or the agitation system. In certain embodiments, the computing device  430  is an article of manufacture. Examples of an article of manufacture include: a server, a mainframe computer, a laptop, or other special purpose computer having one or more processors (e.g., a Central Processing Unit, a Graphical Processing Unit, programmable processor, and/or a microprocessor) that is configured to execute an algorithm (e.g., a computer readable program or software) to receive data, transmit data, store data, or performing methods, for example. 
         [0038]    By way of illustration and not limitation,  FIG. 4  illustrates the computing device  430  as including: a processor  432 ; a non-transitory computer readable medium  433  having a series of instructions, such as computer readable program steps encoded therein; an input/output means  431  such as a keyboard, a mouse, a stylus, touch screen, a camera, a scanner, or a printer. Computer readable program code  434  is encoded in non-transitory computer readable medium  433 . In certain embodiments, the non-transitory computer readable medium  433  includes data repository  435 . The processor  432  accesses computer readable program code  434 , encoded in non-transitory computer readable medium  433  and executes one or more corresponding instructions  436 . In certain embodiments, the non-transitory computer readable medium  433  comprises one or more hard disk drives, tape cartridge libraries, optical disks, and combinations thereof. 
         [0039]    In certain embodiments the data stored in the data repository  435  of the computing device  430  includes information received from the fluid injection device or agitation system. A log  437  is maintained of the information or data about the communicated information (e.g., date and time of transmission, frequency of transmission . . . etc.) with the computing device  430 . In certain embodiments, Applicants&#39; method reviews, analyzes, or mines log  437  and generates reports. 
         [0040]    In certain embodiments, the data repository  435  comprises any suitable data storage medium, storing one or more databases, or the components thereof, in a single location or in multiple locations, or as an array such as a Direct Access Storage Device (DASD), redundant array of independent disks (RAID), virtualization device, and the like. In certain embodiments, the data repository  435  is structured by a database model, such as a relational model, a hierarchical model, a network model, an entity-relationship model, an object-oriented model, or a combination thereof. For example, in certain embodiments, the data repository  435  is structured in a relational model and stores data as attributes in a matrix. 
         [0041]    In certain embodiments, the desludging storage tank  200  includes (not shown) one or more pumps (e.g., Wilden Pumps PX-15 for chemical &amp; diesel transfer); hosing and/or plumbing (e.g., 120 m per roof injection point); air compressors; cranes (e.g., mob and demob); cabin—lab; laboratory equipment (e.g., for monitoring samples); sludge canons configured to create a vortex, in certain embodiments the cannons are configured to move 660 Metric Tons per hour at 10 bar; power packs (e.g., generators and/or pumps); nozzles for injection points; or a combination thereof. 
         [0042]    In certain embodiments the desludging storage tank  200  is prefabricated, in which the body of the desludging storage tank  200 , and/or the fluid injection device, the fluid delivery system, and/or the controller, and/or the agitation system, and the like are prefabricated as one unit. In other embodiments, the desludging storage tank includes an existing tank body that is retrofitted to include at least one of the fluid injection device, the fluid delivery system, the controller, the agitation system, and the like. 
         [0043]    Referring to  FIG. 5 , a flow chart summarizes Applicants&#39; method for removing sludge deposits from a crude oil storage tank without the entry of one or more persons into that storage tank. Initially the crude oil stored in the desludging storage tank  200  is transferred to a holding tank. At step  502 , the floating roof  305  of the desludging storage tank  200  is lowered for image testing of an inner surface of a storage tank (e.g., the bottom  224  of the desludging storage tank  200 ). To illustrate, the floating roof  305  is lowered, such as to about 0.005-5 meters above the highest peak of the sludge deposited at the bottom  224  of the desludging storage tank  200 . 
         [0044]    At step  504 , the image testing is conducted. In certain embodiments, an acoustic inspection system and/or thermal inspection system is used to measure a volume and/or determine a topology of the sludge sediments in the storage tank. For example, an exemplary acoustic inspection system includes an inspection tool that is inserted into the tank through a suitable access hole in the roof until fully submerged in the liquid. The end of the tool has an angled phased array that produces acoustic beams to scan a sector of the desludging storage tank  200  floor (e.g., bottom  224 ) and wall (e.g., wall  201 ). The sector is a percentage of the floor such as between zero and 100% of the floor, more specifically between 80-100 percent of the floor, and preferably 100% of the floor. To illustrate, a T-Type Acoustic Inspection System measures the volume and topology of sludge sediments on the bottom  224  of the storage tanks  200 . The image is then recorded and the topology evaluated to map lance and/or injection point configuration and strategy. 
         [0045]    Alternatively, or in combination, a thermal inspection system is used to measure a volume and determine a topology of the sludge sediments on an inner surface of the desludging storage tank  200 . Here, the thermal inspection system has no sound interference risks. When combined with spectroscopy, the thermal inspection system is configured to distinguish Oil Paraffin Water and Solids phases. 
         [0046]    In certain embodiments, a computing device, such as computing device  430 , is communicatively connected to the acoustic and/or thermal inspection system to control the image testing. The computing device uses the acquired data to produce an image (e.g., 3D display) of the sediment layer and calculates the volume of sediment using a known geometry of the tank. Sector data from multiple entry points is combined to give 100% coverage of the tank floor, for example. 
         [0047]    At step  506 , the floating roof  305  is lowered above the base place, such as configuring the floating roof  305  to about 2.5 meters above the base plate. At step  508 , the additive/diesel feed rate is configured. For example, the feed rate for the additive in liquid source  320  of  FIG. 3  is set to about 1:6 ratio to the diesel in the liquid source  330 . The volume of feed rate is also configured, for example, to about 2 gallons of additive and 12 gallons of diesel per metric ton of sludge measured, for example, at step  504 . At step  508 , the nitrogen injection rate is also configured and corresponding heater is setup (e.g., 62,500 m3 nitrogen from nitrogen pallets). At step  510 , the lance arrangement is configured and use of injection points is strategized. For example, in certain embodiments, no lances are used and only injection points are utilized. Alternatively, lances are used and their configuration within the desludging storage tank  200  is determined at step  510 . 
         [0048]    At step  512 , the volume of the content of the desludging storage tank  200  is reduced to the residual sludge and gels. The income fill crude is diverted to an alternative tank. For example, the fill crude is diverted to the alternative tank for about 72 to 96 hours. 
         [0049]    At step  514 , heating coils of the desludging storage tank  200  are turned on. At step  516 , the impellers disposed on the desludging storage tank  200  are turned on and optionally, the agitation or recirculation pumps are used to further aid in sludge and/or gel reliquification. 
         [0050]    In certain embodiments, the heating coils, impellers, and recirculation pumps, are individually attached to controller  400  by individual communication links In certain embodiments, operation of the heating coils, impellers, and recirculation pumps, is performed by processor  432  using computer readable program code individually attached to controller  400   
         [0051]    At step  518 , the additive/diesel is injected into the tank at the configured rate of step  508 . For example, the additive/diesel combination is injected into the desludging storage tank  200  via the lances and/or injection points previously described at about 10 Bar pressure. At step  520 , the sludge and/or gel is agitated with nitrogen at the configured rate. For example, warm N2 (e.g., Warm Nitrogen Bubbling Concept at 60 degrees C.) is injected into the desludging storage tank  200  at 10 Bar pressure for about 12 hours. At step  522 , liquefied sludge from the desludging storage tank  200  is pumped to a holding tank and educted, such as in a cracking tower. The cracking tower breaks the large hydrocarbons into smaller groupings via thermal, visbreaking, or coking means, for example. In certain embodiments, the educted chemical additives is reusable. To illustrate, the reusable additive is used at step  518  during another cycle of the method  500 . 
         [0052]    At step  524 , the oil to water ratio of the incoming oil and out going liquefied sludge/gel is compared and a measurement of the tail bottom of the desludging storage tank  200  is made. For example, line samples of water and solid samples are taken after phase separation. 
         [0053]    In certain embodiments, method  500  increases the rate of in tank phase separation in-situ that results in a crude oil layer that is recaptured. Here, the de-emulsification provides in-situ phase separation. When phase separation is completed, the separated water and solids are extracted. In certain embodiments, water is drained using a pump. The water is then treated onsite using hydro-cyclone and O-zone methodology, for example. The non-hydrocarbon solids are removed from the desludging storage tank  200  using a vacuum truck. 
         [0054]    At step  526 , a determination is made whether to continue or stop the desludging method  500 . If the determination is to end, the method  500  proceeds from step  526  to step  528  and the method  500  is ended. Alternatively, if the determination is made to continue, method  500  is repeated. In certain embodiments, the entire method (e.g., steps  502  to  526 ) is repeated, while in other embodiments only a portion of method  500 , such as one or more steps of method  500 , are repeated. To illustrate, in certain embodiments, steps  502  and  504  are repeated, while in other embodiments steps  518  to  522  are repeated 5 times and after the fifth step  522 , the method  500  proceeds to step  524  and the determination is made at step  526  to end the desludging method  500 . In another example, the image testing  504  is conducted intermittently after repeated cycles of steps  518  to  522 , such as conducting the image testing at the beginning, at the midpoint, and at the end of a set of cycles of method  500 . 
         [0055]    In certain embodiments, one or more steps of method  500  are omitted or other steps are added. To illustrate, step  522  is omitted and the sludge is not removed from the desludging storage tank  200 . Here, the sludge is liquefied in a closed loop agitation. In another example, impellers or agitation pumps are not used at step  516 . Rather, canon nozzles are inserted (e.g., hydraulically pushed) into the desludging storage tank  200  within the sludge layer using Cold Tap. In this methodology the canons are operated under a nitrogen blanket. Canon nozzles are aligned in the same direction to create a swirling momentum. The canons commence the swirling of the sludge. The centrifugal effect drives the denser water and non additive solids down the conical floor to the edges of the desludging storage tank  200  where they can be decanted/removed from the tank via a pump and valves (4 inch valve). 
         [0056]    In certain embodiments, method  500  is carried out in-line such that the crude oil storage tank is cleaned with limited interruption to refinery operations. Here, the desludging of the tank is carried out without a cleaning crew entering the tank to clean it. Phase separation occurs and the additive is recaptured and reused. Consequently, there is no holding tank closure, which would result in down time due to the desludging storage tank being offline (saving $USD500,000 to 1 million dollars per day). 
         [0057]    The schematic flow chart diagrams included are generally set forth as a logical flow-chart diagram (e.g.,  FIG. 5 ). As such, the depicted order and labeled steps are indicative of one embodiment of the presented method. In certain embodiments, other steps and methods are conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types are employed in the flow-chart diagrams, they are understood not to limit the scope of the corresponding method (e.g.,  FIG. 5 ). Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow indicates a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown. In certain embodiments, individual steps recited in  FIG. 5  are combined, eliminated, or reordered. 
         [0058]    In certain embodiments, Applicants&#39; invention includes instructions residing in the memory, such as memory  133  ( FIG. 1 ) and/or memory  143  ( FIG. 1 ), where those instructions are executed by system processor  132  ( FIG. 1 ) and/or processor  142  ( FIG. 1 ), to performs steps  220 ,  230 ,  240 ,  250 ,  260 ,  270 , recited in  FIG. 2 , and/or steps  310 ,  320 ,  330 ,  340 ,  350 ,  360 ,  370 , and/or  380 , recited in  FIG. 3 , and/or to steps  410 ,  420 ,  430 ,  440 ,  450 ,  460 , and/or  470 , recited in  FIG. 4 , and/or steps  510 ,  520 ,  530 ,  540 ,  550 ,  560 , and/or  570 , recited in  FIG. 5 , and/or steps  610 ,  620 ,  630 ,  640 ,  650 ,  660 , and/or  670 , recited in  FIG. 6 . 
         [0059]    In other embodiments, Applicants&#39; invention includes instructions residing in any other computer program product, where those instructions are executed by a computer external to, or internal to, system  100 , to perform steps  220 ,  230 ,  240 ,  250 ,  260 ,  270 , recited in  FIG. 2 , and/or steps  310 ,  320 ,  330 ,  340 ,  350 ,  360 ,  370 , and/or  380 , recited in  FIG. 3 , and/or to steps  410 ,  420 ,  430 ,  440 ,  450 ,  460 , and/or  470 , recited in  FIG. 4 , and/or steps  510 ,  520 ,  530 ,  540 ,  550 ,  560 , and/or  570 , recited in  FIG. 5 , and/or steps  610 ,  620 ,  630 ,  640 ,  650 ,  660 , and/or  670 , recited in  FIG. 6 . In either case, the instructions may be encoded in an information storage medium comprising, for example, a magnetic information storage medium, an optical information storage medium, an electronic information storage medium, and the like. By “electronic storage medium,” Applicants mean, for example, a device such as a PROM, EPROM, EEPROM, Flash PROM, compactflash, smartmedia, and the like. 
         [0060]    While various embodiments have been described above, it should be understood that they have been presented by way of example only, not limitation, and various changes in form and details may be made. Any portion of the apparatus and/or methods described herein may be combined in any combination, except mutually exclusive combinations. The embodiments described herein can include various combinations and/or sub-combinations of the functions, components and/or features of the different embodiments described. For example, multiple, distributed qualification processing systems can be configured to operate in parallel. 
         [0061]    Although the present invention has been described in detail with reference to certain embodiments, one skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which have been presented for purposes of illustration and not of limitation. Therefore, the scope of the appended claims should not be limited to the description of the embodiments contained herein.