In oilfield applications, pump assemblies are commonly invoked for pumping fluids at high pressures downward from the well surface downhole to a wellbore. Such oilfield operations frequently involve hydraulic fracturing. For hydraulic fracturing, abbreviated “fracking” herein for convenience, typically huge volumes of water and millions of pounds of abrasive-containing fluid such as sand and other primarily abrasive, solid crush-resistant particulate fracking materials Such primarily abrasive fracking materials are termed “proppant”; the combination of sand and concomitant proppant abrasive materials being termed “frac sand” herein. Frac sand and frac fluid, primarily comprising water, are pumped through the wellbore under extreme pressure and into targeted hydrocarbon reservoir regions proximal thereto, to create side “fractures” within the underlying hydrocarbon formations. As is well known in the art, in order to create such fractures, frac fluid containing abrasive proppant should preferably be pumped at extremely high pressures not only to facilitate fracture-creation, but also to sustain the propped-open subsurface structures. As will be appreciated by those skilled in the art, these propped-open structures afford additional pathways for hydrocarbon deposits to be urged to flow from underground formations to the well surface, thereby enhancing well production.
Prior art apparatus and methodology for transporting frac fluid containing frac sand suffer from several long-standing disadvantages. For instance, after being loaded onto either special-purpose pneumatic trucks or railcars, frac sand has typically not been well sealed from environmental incursions during transfers. As a consequence of such environmental incursions, the integrity of this frac sand has been seriously undermined whereupon significant degradation attributable to cumulative effects of abrasion and friction, and exposure to moisture and rain occur during material transfer operations. Since it has been difficult, if not virtually impossible, for a special-purpose railcar to be brought sufficiently close to well sites, prevalent contemporary practice has been for several material transfers to be prerequisite for ultimate delivery of an adequate quantity of frac sand to the intended well site so that fracking operations may be initiated.
Moreover, pneumatic trucks have frequently proven to be unavailable, thereby causing unloading of frac sand and the like from such special-purpose trucks or railcars to be likewise frequently delayed. It should be evident to those skilled in the art that a consequence of these multi-level delays is that railcars remain idle while substantial railroad demurrage fees accumulate. As, unfortunately, has become common in the art, under current fracking protocol, workers unavoidably are exposed to silica particles released during pneumatic transfer of frac sand. Another seemingly unavoidable disadvantage of the prior fracking art is that frac sand is frequently transferred from railcars to silos for storage. To achieve this sand storage capability at the transload facility, substantial capital costs of silos construction are incurred. According to the present invention, such sand storage silos and the like are rendered unnecessary because frac sand would preferably be stored in situ in the container framework hopper. Ergo, such containers can be stored and stacked on the ground independently of any associated railcars and pneumatic trucks—in the absence of silos.
Also well established in the fracking art is that once special-purpose trucks or railcars have transported frac sand to the prescribed well site at which fracking operations will occur, these trucks or railcars are returned empty to the point of origin to be reloaded and to effectuate another delivery of frac sand to the same or to another prescribed well site. Such a procedure obviously is not cost-effective and, on the contrary, is wasteful since substantial expense is incurred transporting these trucks or railcars that are devoid of any solid materials or liquid cargo.
Accordingly, what is needed in the art is an apparatus and associated methodology for improving logistics of transporting frac sand proximal to well sites to inherently avoid such several long-standing prior art limitations and disadvantages, and thus enabling temporarily storing and transporting of frac sand to well sites preferably via conventional flatbed truck trailers and conventional flatbed railcars, and for contemporaneously temporarily storing and transporting frac fluids, i.e., spent water and associated hydrocarbon liquids from the well site back to the frac sand supplier and/or back to a water recycle facility.
As will become clear to those skilled in the art, this need is fulfilled by embodiments of the present invention which contemplate novel application of suitably configured container frameworks, including, but not limited to, standard International Organization for Standardization (“ISO”) shipping containers, constructed with internal structures for supporting and strengthening the internal walls and floor thereof, and a valve apparatus preferably configured to efficiently and securely achieve prerequisite frac sand transfer from such suitably configured container framework to well site fracking operations, regardless of the remoteness and limited accessibility of a diversity of well site locations.
It is an object and advantage of the present invention to provide a well-sealed temporary storage and transport container to inherently avoid environmental incursions thereinto which tends to undermine integrity of frac sand because of degradation attributable to cumulative effects of exposure to moisture and rain, and to abrasion and friction during material transfer.
It is an object of the present invention to avoid undue delay of transfer of frac sand from suppliers' facilities to well site locations due to unavailability of special purpose pneumatic trucks and railcars.
It is another object of the present invention to reduce hazardous exposure during fracking operations that threatens both workers and the environment.
It is yet another object and advantage of the present invention to provide a dual modality storage and transport container with simplified bladder valves enabling loading frac sand at a frac sand supplier's location, transferring and unloading such stored frac sand at the well site, and then enabling spent frac fluid comprising primarily flow-back water and associated small amounts of liquid hydrocarbons, to be loaded thereinto, and transported to a recycle water facility.