Patent Application
20160177643
The field to which the disclosure generally relates to includes apparatus and methods for supplying and metering fiber introduction into fluids, and in particular, supplying and metering fiber into fluids useful in oilfield applications.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
The production of hydrocarbons from an oilfield occurs primarily through a wellbore penetrating a subterranean formation. The wellbore may include access to fractures extending radially into surrounding geologic formations. Such fractures may be beneficial to hydrocarbon production, and may be created by a fracturing operation performed in advance of hydrocarbon production in order to intentionally form fractures extending from the wellbore into a subterranean formation. That is, the well may display an architectural profile having a variety of particularly located fracture sites built thereinto in an effort to maximize hydrocarbon production from the well.
In a fracturing operation, a fracturing fluid may be pumped at high pressure into the wellbore to form the fractures and stimulate production of the hydrocarbons. The fractures may serve as channels through the formation through which hydrocarbons may reach the wellbore. Fracturing fluid may also include a solid particulate referred to as proppant, which may be placed in or primarily within the fracture(s) during or after their formation, and maintain the fracture(s) propped open.
In certain circumstances, the proppant or other particulate contaminants from the surrounding formation may fail to remain in place. For example, fracturing or other fluid may flow back into the wellbore from the fractures bringing the proppant and other particulates along in a circumstance referred to as “flowback”. When this occurs, hydrocarbon production is impeded as opposed to being enhanced. This is a common occurrence in the case of unconsolidated formations as well as those that have undergone gravel packing and other treatments that add particulate to the well.
To help avoid the flowback of fracturing fluid and proppant, or other solid particulate into the wellbore, methods have been developed in which fibers are added to the fracturing fluid in order to provide the fluid with a flowback inhibiting character. The incorporation of such fibers into the fracturing fluid may substantially prevent the flowback of proppant into the wellbore. The fibers may provide the fracturing fluid with characteristics that inhibit the flowback of fracturing fluid and proppant along with any other solid particulate. That is, the fracturing fluid may display a web-like character that acts to trap particulate at a fracture and other sites of the well, thus substantially preventing their flowback. Flowback inhibiting fibers are added to the fracturing fluid at the well site during, or immediately prior to, the delivery of the treatment fluid to the well. In this manner, the web-like character of the fracturing fluid is fully achieved upon its arrival downhole (e.g. within a fracture) rather than at a random location within the borehole.
When adding fibers to the fluid at the wellsite, the fibers have traditionally been difficult to handle and meter at target concentrations in fracturing operations. The same is the case for cementing operations as well which can include the incorporation of fibers into cementing fluids. Problems that typically arise with the existing fiber metering and delivery systems involve the fibers jamming the metering equipment and plugging conveyance chutes. Thus, there is a need for improved fiber metering and delivery systems which avoid the above described problems, and such need is addressed, at least in part, by embodiments described in the following disclosure.
This section provides a general summary of the disclosure, and is not necessarily a comprehensive disclosure of its full scope or all of its features.
In a first aspect of the disclosure, an apparatus, which controls and meters the feed of fibers into a fluid, is provided. The apparatus includes a housing having an intake opening and a discharge opening, two or more toothed metering elements mounted on a plurality of spindles, and a shear bar disposed within the housing above and between the toothed metering elements. The spindles are rotatably mounted within the housing. A fluid is disposed adjacent the discharge opening for receiving fibers. In some cases, a mass of fibers is introduced into the apparatus via the intake opening, the mass of fibers contacts the shear bar and the toothed metering elements, and delivery of the fibers to the fluid is metered by controlling rotational speed of the toothed metering elements. The plurality of spindles with toothed metering elements may be two spindles, and the spindles may rotate in opposite directions. The mass of fibers may be divided into substantially discrete fibers by the contact with the shear bar and the toothed metering elements, and the discrete fibers delivered to the liquid by passing through the apparatus.
In some aspects, the spindles are drums, each having one or more slots disposed on the surface of such drum, the slots orientated parallel with an axial centerline of the drum, and the slots may accommodate inserts including the toothed metering elements. Each of the drums may further include distally positioned axles disposed upon the axial centerline of the drum and extending from each end of the drum, a retainer cap disposed over each axle and mated with the drum to secure the inserts, and a lock for securing the retainer cap over the axle. In some aspects, the ends of each drum may serve as an axle. The axles may extend through walls of the housing, and be rotatable secured within.
The shear bar may function as a shearing surface for the toothed metering elements to work against. The shear bar may further help prevent fiber loaded into the apparatus just above the drums from jamming between the spindles. Further, teeth on the toothed metering elements may tear into the fiber and shear the fiber against the shear bar to separate the fiber, and meter fiber discharge through the discharge opening.
The fluid may be any fluid requiring fiber added thereto, and may include oilfield fluids such as fracturing fluid, cementing fluid, drilling fluid, gravel packing fluid, and the like.
In another aspect of the disclosure, a system is provided which includes a fiber feed control apparatus having a housing having an intake opening and a discharge opening, a mass of fibers received at the intake opening, a plurality of toothed metering elements mounted on a plurality of spindles (the spindles rotatably mounted within the housing) a shear bar disposed above and between the plurality of toothed metering elements, and fibers to be discharged at the discharge opening. The system further includes a fluid disposed adjacent the discharge opening for receiving and mixing with the fibers discharged by the fiber feed control apparatus. In some aspects, the spindles are drums, each having one or more slots disposed on the surface of such drum, the slots orientated parallel with an axial centerline of the drum, and the slots may accommodate inserts including the toothed metering elements. Each of the drums may further include distally positioned axles disposed upon the axial centerline of the drum and extending from each end of the drum through walls of the housing, and be rotatably secured within the housing, and may further include a retainer cap disposed over each axle and mated with the drum to secure the inserts, and a lock for securing the retainer cap over the axle. The drums may be two drums which rotate in opposing directions. The fluid may be any fluid requiring fiber added thereto, and may include oilfield fluids such as fracturing fluid, cementing fluid, drilling fluid, gravel packing fluid, and the like.
Yet another aspect includes a system for preparing a subterranean formation treatment fluid, the system including an apparatus having a housing with an intake opening and a discharge opening, a mass of fibers received at the intake opening, a plurality of toothed metering elements mounted on a plurality of drums, a shear bar disposed above and between the plurality of toothed metering elements, a treatment fluid disposed adjacent the discharge opening, and fibers to be discharged from the discharge opening. The fibers are continuously discharged at a substantially constant rate and added to the treatment fluid.
Certain embodiments of the disclosure will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying figures illustrate the various implementations described herein and are not meant to limit the scope of various technologies described herein, and:
The following description of the variations is merely illustrative in nature and is in no way intended to limit the scope of the invention, its application, or uses. The description and examples are presented herein solely for the purpose of illustrating the various embodiments of the invention and should not be construed as a limitation to the scope and applicability of the invention. While the compositions of the present invention are described herein as comprising certain materials, it should be understood that the composition could optionally comprise two or more chemically different materials. In addition, the composition can also comprise some components other than the ones already cited. In the summary of the invention and this detailed description, each numerical value should be read once as modified by the term “about” (unless already expressly so modified), and then read again as not so modified unless otherwise indicated in context. Also, in the summary of the invention and this detailed description, it should be understood that a concentration, amount or measurement range listed or described as being useful, suitable, or the like, is intended that any and every concentration or amount or measurement within the range, including the end points, is to be considered as having been stated. For example, “a range of from 1 to 10” is to be read as indicating each and every possible number along the continuum between about 1 and about 10. Thus, even if specific data points within the range, or even no data points within the range, are explicitly identified or refer to only a few specific, it is to be understood that inventors appreciate and understand that any and all data points within the range are to be considered to have been specified, and that inventors possession of the entire range and all points within the range.
Unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by anyone of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).
In addition, use of the “a” or “an” are employed to describe elements and components of the embodiments herein. This is done merely for convenience and to give a general sense of concepts according to the disclosure. This description should be read to include one or at least one and the singular also includes the plural unless otherwise stated.
The terminology and phraseology used herein is for descriptive purposes and should not be construed as limiting in scope. Language such as “including,” “comprising,” “having,” “containing,” or “involving,” and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited.
Also, as used herein any references to “one embodiment” or “an embodiment” means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily referring to the same embodiment.
Some aspects of the disclosure relate to apparatus useful for separating a mass of fibers and introducing the separated fibers to fluids. The fibers may be delivered to the fluid by gravity, pressure, mechanical manipulation, or any other suitable device or method for moving fibers into fluid after separation. The mass of fibers may be introduced into the apparatus by gravity, pressure, mechanical manipulation, or any other suitable device or method, as well. The fluid containing the discrete fibers may, in some cases, be useful for subterranean formation fracturing and/or wellbore cementing applications. However, other types of oilfield applications and fluids may realize benefits afforded by embodiments described herein. For example, drilling applications may employ techniques described herein. Regardless, some embodiments described herein employ an apparatus to deliver fiber, from a readily transportable fibrous mass supply thereof, to an oilfield application fluid on-site.
Referring now to
The fracturing fluid mixture 102 may be provided to the well 110 after preparation in a mixing system 150. Once the mixture 102 is attained it may be directed through the well 110 by a series of high pressure pumps. For example a series of conventional large scale triplex pumps (not shown) may be employed together, linked through a common manifold and coupled to the well head 175. The combined output of these pumps may be mechanically collected and distributed according to the parameters of the fracturing operation. The fracturing fluid mixture 102 may thus be driven into the well formation 199 for fracturing rock and forming fractures 112 as described above. In one embodiment, a series of between about 4 and about 20 triplex pumps are provided at the oilfield 100 for such a fracturing operation.
The fracturing fluid mixture 102 is provided to the high pressure pumps for fracturing from a mixing system 150. That is, a mix system 150 may be provided whereat constituents 104 and 106 are combined to form the fracturing fluid mixture 102 just prior to its high pressure downhole injection as described above. An exit pipe 155 may be employed to carry the mixture 102 from the mix system 150 to the above noted pumps or other post-mix processing locations at the oilfield 100. Regardless, constituents 104 and 106 are combined at the oilfield 100 to form the fracturing fluid mixture 102 at the time of the fracturing operation. As described below, this allows the fracturing fluid mixture 102 to be advanced throughout the fracturing equipment at the oilfield 100 and through the well 110 prior to taking on any sticky gel-like properties or a web-like character that might otherwise impede such advancement.
Continuing with reference to
Regardless of whether the components of the fracturing fluid 106 are pre-mixed or individually fed to the mix system 150, the fiber 104 is individually provided to the mix system 150, and in some instances, upon addition of the fracturing fluid 106 or its components thereto. The fiber 104 may provide a web-like character to the fracturing fluid mixture 102 once dispersed therethrough. A process of congealing may ensure that, within a matter of under a few hours, a web-like character is imparted into the fracturing fluid mixture 102 that substantially prohibits its free flow of movement through the described oilfield delivery equipment. As also described below, this may be of benefit in avoiding flowback of the fracturing fluid mixture 102 into the well 110 from the production region 130. However, this characteristic of the fiber 104 provides good reason to have the fiber 104 separately added to the fracturing fluid 106 as opposed to providing a pre-mixed, most likely unworkable, fracturing fluid mixture 102 with fiber 104 already blended therein.
Given that the fiber 104 is to be separately or individually added to the mix system 150 as indicated, a fiber feed control apparatus 140 may be provided to receive a fiber mass 142 and discharge the fiber 104 to the mix system 150. Although specific embodiments of the fiber feed control apparatus 140 are described below, the fiber feed control apparatus 140 may be any apparatus appropriate for metering, separating and optionally cutting, fiber mass 142 as fibers 104 are delivered to the mixing system 150.
In some embodiments of the disclosure, the fiber feed control apparatus 140 is a housing having an intake opening and a discharge opening with several toothed metering elements mounted on a pair of spindles, such as a rod, pin, cylinder, or shaft, serving as an axis that revolves the mounted toothed metering elements. The spindles are rotatably mounted to and within the housing. A shear bar is disposed above and between the plurality of toothed metering elements. The shear bar provides shearing surface for the toothed metering elements to work against, and also may help prevent fiber mass introduced into the housing above the spindles from jamming in between the spindles, as the spindles are rotated and fibers move there between. In operation, the spindles rotate towards each other such that teeth on the toothed metering elements act as paddles that move fiber down from the inside of the housing and out of the discharge opening below the spindles. For packed fiber masses, the teeth may tear into the fiber and shear the fiber against the shear bar to separate the fiber into more discrete particles, and meter through the discharge opening.
In some other aspects, a vertical-sided hopper, such as 144 in
Referring now to
Now referring to
Referring now to
For a fracturing application such as that described above, the fiber 680 may be delivered to the mix system or fluid in fragments of between about 5 mesh and about 100 mesh. Additionally, the fiber 680 may be made up of a natural or synthetic glass, polymeric material, ceramic, metal, and the like. In some aspects of the disclosure, fiber 680 of the same or similar type and characteristics may be employed as part of a cement slurry mixture 513 as detailed further below.
Continuing now with reference to
A cement slurry mixture 704 is delivered to the well 702 in order to secure a borehole casing 706 in place within the formation 708. Cementing in this manner may follow drilling of the well 702 itself where a drill bit is rotatably driven into the formation to drill the well 702 with the aid of drilling and circulating mud. Subsequent cementing may take place wherein a delivery pipe 710 is driven past uphole sections of in place borehole casing 712, through a cement plug 714 and to un-cemented downhole borehole casing 706. A cement slurry mixture 704 is then delivered downhole and forced between the casing 706 and the formation 708 for securing the casing 706 in place. Large scale cement pumps may be employed to deliver the cement slurry mixture 704 as shown. A cementing application such as that described above may take place in advance of, or in addition to, a fracturing application as also detailed herein. That is, depending on the design of the overall completion operation, fracturing and cementing techniques may both be employed for the purpose of furthering removal of hydrocarbons, again, generally oil and natural gas, from the formation 708.
Continuing with reference to
The cement slurry mixture 704 may be provided to the well 702 after preparation in a mixing system 750. Once the mixture 704 is attained it may be directed through the well 702 by one or more pumps. For example a series of conventional large scale triplex or quintuplex pumps (not shown) may be employed together, linked through a common manifold and coupled to the well head 758. An exit pipe 755 may be employed to carry the mixture 704 from the mix system 750 to the above noted pumps or other post-mix processing locations at the oilfield 100.
The fiber 716 may provide a web-like character to the cement slurry mixture 704. The web-like character may take hold in relatively short order. For example, the flow of mud and other contaminants may be substantially eliminated within a matter of hours, even prior to the complete setting and hardening of the mixture 704 between the casing 706 and the formation 708. This helps prevent undesirable flowback as noted above, safeguarding cementing equipment. However, as in the case of fracturing, the nature of the mixture 704 also calls for the addition of fiber 716 only on site at the time of the operation rather than by way of pre-blending into the slurry 718 off-site. Also, fiber 716 may be added to the mix system 750 at a suitable rate for cementing operations, such as between about 1 kgs and about 20 kgs per minute.
The above described embodiments allow for the controlled and metered addition of flowback inhibiting fibers to oilfield fluid mixtures without requiring a significant amount of manual labor. This is achieved by the employment of a fiber feed control apparatus, which, as detailed above, may be employed to drastically reduce the human cost incurred that results from the necessity of on-site fluid mixture blending. Additionally, the use of a fiber feed control apparatus provides a degree of precision in the metering or rate of fiber addition to the application fluid mixture heretofore unavailable.
The foregoing description of the embodiments has been provided for purposes of illustration and description. Example embodiments are provided so that this disclosure will be sufficiently thorough, and will convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the disclosure, but are not intended to be exhaustive or to limit the disclosure. It will be appreciated that it is within the scope of the disclosure that individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
Also, in some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. Further, it will be readily apparent to those of skill in the art that in the design, manufacture, and operation of apparatus to achieve that described in the disclosure, variations in apparatus design, construction, condition, erosion of components, gaps between components may be present, for example.
Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
Although a few embodiments of the disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.
