Patent Application
20250075603
The invention relates to hydraulic fracturing in hydrocarbon extraction and more particularly to a device and process for addressing the problem of screen-outs where sand and other materials cause blockages in fractures and prevent efficient extraction of hydrocarbons.
Hydraulic fracturing is a technique used to extract hydrocarbons from underground rock formations. This technique involves injecting a high-pressure fluid mixture into an isolated zone of a wellbore to create fractures in the rock. These fractures allow the trapped hydrocarbons to flow more freely, increasing the production rates.
During the hydraulic fracturing process, proppants are commonly added to the fluid. Proppants, such as sand or ceramic beads, are solid materials that help keep the fractures open once the pressure is released.
In the context of hydraulic fracturing operations, the term “screen-outs” refers to a problem that can occur during the fracturing process. A screen-out occurs when the proppant or other solid materials used in the fracturing fluid fail to flow down the fracture and accumulate and block the fractures. If the situation is not alleviated, then pumping pressures may begin to increase and may lead to a premature shutdown of the job leaving proppant in the wellbore. To continue the fracturing process or to begin production from the well, the proppant that was left in the wellbore will either have to be flowed to surface or cleaned out by use of mechanical means.
Screen-outs can happen due to several factors, such as (i) inadequate fracture design which causes excessive proppant accumulation at certain points, (ii) excessive fracturing pressure which causes reduced pump rates, making it easier for proppants to become trapped, (iii) insufficient fluid carrying capacity, which can cause settling of the proppant, and (iv) the geology and properties of the rock formation being fractured can have complex or unpredictable fracture networks which may be more prone to proppant accumulation and blockages. These are common factors causing screen-outs. Other factors may contribute to development of screen-outs.
Screen-outs can have significant consequences for hydraulic fracturing operations. They can reduce the efficiency of the wellbore completions operations, lower production rates by having incomplete fracture jobs, and increase costs by inducing unplanned work. Screen-outs can also cause excessive downhole pressure that has the potential to damage downhole tools, which once damaged, can never be repaired and may lead to the loss of a potentially productive reservoir. Resolving screen-outs typically involves performing remedial operations, such as attempting to flow the blockage to surface using the energy of the well, failing that, using coiled tubing or other tools to remove the accumulated proppants or attempting to open the blocked fractures through various techniques.
To mitigate the risk of screen-outs, engineers and operators employ advanced fracture modeling, data analysis, and monitoring techniques. By optimizing fracture designs, adjusting fluid properties, and monitoring the injection process in real-time, they aim to minimize the occurrence of screen-outs and maximize the productivity of hydraulic fracturing operations.
Despite these efforts to mitigate the risk of screen-outs, unpredictability of factors contributing to screen-outs require other solutions to address screen-outs when they occur. Some examples of remediation of screen-outs are described in U.S. Pat. Nos. 10,030,473 and 10,138,707, each of which is incorporated herein by reference in its entirety.
There remains a need for practical improvements in addressing the problem of screen-outs occurring during hydraulic fracturing operations. A need exists also to protect the integrity of downhole tools during the fracturing process, not only during screen-out conditions but also during normal operations. This may be for example to maintain acceptable pressure differentials across packers or to avoid casing collapse scenarios. A need also exists to maintain the integrity of isolating media between fractured intervals. In the case of closable fracture valves, if the media isolating flow and pressure between fractured intervals is compromised, and the decision is taken to close a valve for example, to shut off water production, then the water has the potential to find a flow path to an adjacent open frac valve.
In accordance with one embodiment of the present disclosure, there is provided a process for generating fluid flow out of a first fracture zone of a well including a liner or casing to remove a screen-out condition and/or to protect one or more downhole tools deployed in the well. The process comprises the steps of providing the casing with a permanent or temporary fluid flow pathway extending from a first fracture zone to an adjacent fracture zone downhole from the first fracture zone, wherein the fluid flow pathway becomes operable when a pre-determined parameter is indicated in the well.
In some embodiments, the fluid flow pathway may be provided by providing the liner or casing with a flow device defined by a channel. The channel may be configured to permit fluid to flow from outside of the casing to an interior cavity of the casing, wherein the channel provides a fluid flow pathway from the first fracture zone to the adjacent fracture zone downhole from the first fracture zone.
In some embodiments, the flow device may be integrated into the liner or casing to form part of the liner or casing.
In some embodiments, the flow device may be configured for use with a fracturing system using a ball-valve activated sleeve or a dart-valve activated sleeve.
In some embodiments, the channel may include a blocking member configured to disengage from the channel when the pre-determined parameter is reached within the channel.
In some embodiments, the pre-determined parameter may be selected as a pressure indicating a screen-out condition and/or a pressure that will cause damage to the one or more downhole tools.
In some embodiments, the channel may further include a shield member which is pushed out of the channel when the blocking member is disengaged from the channel.
In some embodiments, the shield member may be formed of millable or dissolvable material.
In some embodiments, the flow device may be connected to an outer sidewall of the liner or casing.
In some embodiments, the flow device may be configured for use with a coiled tubing activated sleeve.
In some embodiments, the channel may include a blocking member configured to disengage from the channel when a pre-determined pressure is reached within the channel.
In some embodiments, the first fracture zone may be a plugged and perforated zone isolated by a set of fracturing plugs and the fluid flow pathway may be provided by remotely disengaging a lower fracturing plug of the set of fracturing plugs and allowing the lower fracturing plug to move in the downhole direction to extend a length of the first fracture zone until it encompasses an area of the adjacent fracture zone.
In accordance with another embodiment of the present disclosure, there is provided a flow device for generating fluid flow out of a first fracture zone of a well including a liner or casing to remove a screen-out condition and/or to protect one or more downhole tools deployed in the well. The device may include a main body defined by a channel, the channel may be configured to permit fluid to flow from outside of the liner or casing to an interior cavity of the liner or casing, wherein the channel provides a fluid flow pathway from the first fracture zone to the adjacent fracture zone downhole from the first fracture zone and a sub-casing configured to permit the sub-casing to form a part of the liner or casing.
The flow device may be configured for use with a fracturing system, a using ball-valve activated sleeve or a dart-valve activated sleeve.
In some embodiments of the flow device the channel may include a blocking member configured to disengage from the channel when a pre-determined parameter is reached within the channel.
In some embodiments of the flow device, the pre-determined parameter may be selected as a pressure indicating a screen-out condition and/or a pressure that will cause damage to the one or more downhole tools.
In some embodiments of the flow device, the channel may further include a shield member which is pushed out of the channel when the blocking member is disengaged from the channel.
In some embodiments of the flow device, the shield member may be formed of millable or dissolvable material.
In some embodiments of the flow device, the main body may be further defined by a fracturing channel providing a flow path to form a fracture or to treat a prior-formed fracture.
In some embodiments of the flow device, the flow device is configured for use with a coiled tubing activated sleeve.
In some embodiments of the flow device, the main body comprises an internal sliding sleeve configured to open and close the fracturing channel.
In the Detailed Description section below, one or more embodiments of the present technology are described in relation to the attached figures. These embodiments are intended to provide a better understanding of the technology, how the technology may be put into practice, and to demonstrate certain advantages of the technology. The drawings are not necessarily to scale. Instead, emphasis is placed upon illustrating the principles of various embodiments of the invention. Similar reference numerals indicate similar components.
In screen-out conditions (also known as “pressure out” conditions) occurring during hydraulic fracturing, the fluid flow pathways into fractures become blocked by sand or other materials, generating a plug which causes excessive pressure to build in the isolated fracturing zone. This requires suspension of operations to prevent a catastrophic failure and such suspensions are undesirable due to associated costs.
If a screen-out occurs, the sand and slurry must be removed before fracturing operations can resume. Options for dealing with screen-outs may include (i) flowing the sand slurry back to surface using the energy of the fracture that was just pumped and the pressure of the reservoir (ii) stop the fracturing operation and clean out the well using a coiled tubing cleaning system, and (iii) if coiled tubing activated sleeves are used in the fracturing process, the sand slurry can be circulated out of the well to the surface. Implementation of any of these options cause unplanned work stoppages and can be detrimental to other components of the well such as downhole tools and well casing. For example, the cost in Canadian dollars to undertake the flow back process is in the range of $15,000 to $20,000, requiring at least about two hours. The clean out process may cost between about $400,000 to $500,000 with a delay of 2-4 days. If the clean out process is unsuccessful and fractured intervals below the screened-out zone remain incapable of producing hydrocarbons, losses can amount to more than $170,000 per interval.
An added complication is that a screen-out condition combined with high bottom-hole pressures can cause downhole fracturing sleeves and associated equipment to become damaged and prevent additional fractured zones from being properly stimulated or re-fractured, causing additional losses.
The present inventor has conceived of a solution for addressing the problem of screen-outs which is applicable to the four commonly used fracturing processes used in North America; (i) plug and perforate systems, (ii) systems using ball activated sleeves with seats where the sleeves are cemented or paired with open hole packers, (iii) systems using coiled tubing activated sleeves, and (iv) ball or dart activated sleeves without internal diameter restrictions.
The solution to the screen-out problem developed by the present inventor is to provide an engineered bypass mechanism triggered by well conditions such as pressure or triggered by remote actuation. Generation of a bypass or alternative flow path provides a new pathway for the sand or other material generating the plug to be pumped away from the blockage area and further downhole into another fracture, thereby enabling stimulation and production to continue.
Various embodiments of processes, systems and devices used to implement the subject technology are described below.
An embodiment 100 of a screen-out flow system is illustrated in
It is seen in
An embodiment 200 of a screen-out flow system is illustrated in
Turning now to
The main body 621 includes a sliding internal sleeve 622 to provide alignment of the fracturing channel 623 with openings in the sleeve body 621 (the openings are not shown, to preserve clarity). The internal sleeve 622 slides in the direction of the dot-dashed arrows to provide this alignment.
One embodiment of a process for generating flow in a screened-out fracture zone generated in a plug and perforate system is illustrated in
Other than described herein, or unless otherwise expressly specified, all numerical ranges, amounts, values and percentages, such as those for amounts of materials, elemental contents, times and current rate, ratios of amounts, and others, in the following portion of the specification and attached claims may be read as if prefaced by the word “about” even though the term “about” may not expressly appear with the value, amount, or range. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained. At the very least, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
The terms “approximately,” “about,” “substantially,” and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numeral ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and are considered to be within the scope of the disclosure.
The articles “the”, “a” and “an” are not necessarily limited to mean only one, but rather are inclusive and open ended so as to include, optionally, multiple such elements.
“At least one,” in reference to a list of one or more entities should be understood to mean at least one entity selected from any one or more of the entities in the list of entities, but not necessarily including at least one of each and every entity specifically listed within the list of entities and not excluding any combinations of entities in the list of entities. This definition also allows that entities may optionally be present other than the entities specifically identified within the list of entities to which the phrase “at least one” refers, whether related or unrelated to those entities specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) may refer, to at least one, optionally including more than one, A, with no B present (and optionally including entities other than B); to at least one, optionally including more than one, B, with no A present (and optionally including entities other than A); to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other entities). In other words, the phrases “at least one,” “one or more,” and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C,” “at least one of A, B, or C,” “one or more of A, B, and C,” “one or more of A, B, or C” and “A, B, and/or C” may mean A alone, B alone, C alone, A and B together, A and C together, B and C together, A, B and C together, and optionally any of the above in combination with at least one other entity.
Where two or more ranges are used, such as but not limited to 1 to 5 or 2 to 4, any number between or inclusive of these ranges is implied.
As used herein, the phrase, “for example,” the phrase, “as an example,” and/or simply the term “example,” when used with reference to one or more components, features, details, structures, and/or methods according to the present disclosure, are intended to convey that the described component, feature, detail, structure, and/or method is an illustrative, non-exclusive example of components, features, details, structures, and/or methods according to the present disclosure. Thus, the described component, feature, detail, structure, and/or method is not intended to be limiting, required, or exclusive/exhaustive; and other components, features, details, structures, and/or methods, including structurally and/or functionally similar and/or equivalent components, features, details, structures, and/or methods, are also within the scope of the present disclosure.
The term “comprising” is intended to be open and permits but does not require the inclusion of additional elements or steps. When the term “comprising” is used herein, the term “consisting of” is thus also encompassed and disclosed. Where ranges are given, endpoints are included. Furthermore, it is to be understood that unless otherwise indicated or otherwise evident from the context and understanding of one of ordinary skill in the art, values that are expressed as ranges can assume any specific value or subrange within the stated ranges in different embodiments, to the tenth of the unit of the lower limit of the range, unless the context clearly dictates otherwise. Where the term “about” is used, it is understood to reflect +/−10% of the recited value. In addition, it is to be understood that any particular embodiment that falls within the prior art may be explicitly excluded from any one or more of the claims. Since such embodiments are deemed to be known to one of ordinary skill in the art, they may be excluded even if the exclusion is not set forth explicitly herein.
In addition, it is to be understood that any particular embodiment of the present disclosure that falls within the prior art may be explicitly excluded from any one or more of the claims. Since such embodiments are deemed to be known to those of ordinary skill in the art, they may be excluded even if the exclusion is not set forth explicitly herein. Any particular embodiments of compositions disclosed herein can be excluded from any one or more claims, for any reason, whether or not related to the existence of prior art.
All cited sources, for example, references, publications, databases, database entries, and art cited herein, are incorporated into this application by reference, even if not expressly stated in the citation. In case of conflicting statements of a cited source and the instant application, the statement in the instant application shall control.
This application claims the benefit of priority to U.S. Provisional Application No. 63/536,779 filed on Sep. 6, 2023, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63536779 | Sep 2023 | US |
