DRILLING FLUID TREATMENT PROCESS AND SYSTEM

Description

CROSS REFERENCED APPLICATIONS

The present application claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 63/678,654 titled “Drilling Fluid Treatment Process and System” filed Aug. 2, 2024, the disclosure of which is incorporated herein by reference in its entirety

FIELD

This patent application relates to apparatus and methods for treatment of drilling fluids used in hydrocarbon prospecting. Specifically, a process and system are described for treating oil- and water-based drilling fluids to separate solids from liquids.

BACKGROUND

Drilling fluids help lubricate a drill bit that is in the process of extending a well into the earth, and they remove material loosened by the drill bit from the well. Drilling fluids are commonly water-based or oil-based. The drilling fluids are pumped into a wellbore during drilling and circulated out of the wellbore to the surface, bringing with them subterranean solid and liquid materials. Components of the drilling fluid may be recovered and recycled into new drilling fluid. In any event, drilling fluids bearing subterranean materials that are surfaced from a wellbore must be treated to separate solids, water, and organic materials. Efficient, effective methods for such treatment are always needed.

SUMMARY

Embodiments described herein provide a method of treating a water-based stream containing solids, the method comprising mixing the water-based stream containing solids, or a material derived from the water-based stream containing solids, with a flocculant agent, a coagulant agent, or both to form a mixture; routing the mixture to a high efficiency separator to yield a solids stream and a liquid stream; and routing the solids stream to an electro-osmotic filter press to form a solid filter cake.

Other embodiments described herein provide a method of treating a fluid stream containing solids, the method comprising mixing the fluid stream containing solids, or a material derived from the fluid stream containing solids, with a flocculant agent, a coagulant agent, or both to form a mixture; routing the mixture to a high efficiency separator to yield a solids stream and a liquid stream; determining whether the fluid stream containing solids is a water-based stream, determining whether the liquid stream is a water stream, or both; and where the fluid stream containing solids is a water-based stream, the liquid stream is a water stream, or both, routing the solids stream to an electro-osmotic filter press to form a compressed solid material.

In other embodiments, the system and method use an in-line mixer in conjunction with the mixing vessel to mix the mixture.

In yet other embodiments, at least a portion of the water-based stream containing solids is routed to a bulk separator and the material derived from the water-based stream from an effluent of the bulk separator is formed.

In still other embodiments, diluent is added to the high efficiency separator to control the operation thereof.

In some embodiments, the process is configured to manage both aqueous and/or non-aqueous fluid streams.

In still yet other embodiments, a controller operates a diverter to route the solids stream to the electro-osmotic filter press.

In yet other embodiments, the fluid stream containing solids is a non-aqueous stream, the liquid stream is a non-aqueous stream, or both, and the diverter operates to route the solids stream away from the electro-osmotic filter press.

Some embodiments are directed to a system for processing drilling fluids where the system has a bulk separator containing an effluent. The system also has a mixing vessel in fluid communication with the bulk separator such that the mixing vessel can receive at least a portion of the effluent and wherein the mixing vessel is configured to receive a mixing agent. The effluent and the mixing agent combine to become a mixture. The system also has a drying module wherein the drying module has a high efficiency separator configured to receive at least a portion of the mixture wherein the high efficiency separator separates the mixture into a solid stream and a liquid stream. The system ultimately has a press mechanism in fluid communication with the high efficiency separator and configured to receive the solid stream, wherein the press mechanism compresses the solid stream into a compressed solid material and a solid-free liquid.

In other embodiments, the mixing agent is a flocculant agent, a coagulant agent or both.

In yet other embodiments, the high efficiency separator is a centrifuge.

In still other embodiments, the press mechanism is an electro-osmotic filter press.

In some embodiments, the system has a first and a second sensor, wherein the first sensor is coupled to the mixing vessel and configured to determine the density of the mixture as it enters the high efficiency separator, and wherein the second sensor is coupled to the high efficiency separator and configured to determine the density of the liquid stream. The system can also have a pump configured to pump a diluent stream into the mixture before it enters the high efficiency separator. The system also has a controller operatively coupled with the first and second sensors and the pump such that a first density signal from the first sensor coordinated with a second density signal from the second sensor can be utilized to determine a target density of the mixture.

In still yet other embodiments, the controller is configured to control the pump wherein the pump can pump diluent into the mixture before it enters the high efficiency separator to generate the target density of the mixture.

In yet other embodiments, the system has a solid stream sensor operatively coupled with the high efficiency separator and configured to determine if the solid stream is water-based or non-aqueous.

In still other embodiments, the system has a controller in signal communication with the solid stream sensor and a diverter, wherein if the solid stream is determined to be non-aqueous the diverter can be controlled to an open state and divert the solid stream onto a conveyor system before entering the press mechanism.

In some embodiments, if the solid stream is determined to water-based, the controller can cause the diverter to be in a closed state and divert the solid stream to the press mechanism.

In still yet other embodiments, the system has an inline mixer disposed between the mixing vessel and the high efficiency separator.

This summary is provided to introduce a selection of concepts that are further described in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. Additional features and aspects of embodiments of the disclosure will be set forth herein, and in part will be obvious from the description, or may be learned by the practice of such embodiments

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a system and process flow for treating a water-based stream containing solids in accordance with embodiments of the present disclosure.

FIG. 2 illustrates a system and process flow for treating a water-based stream containing solids in accordance with embodiments of the present disclosure.

FIG. 3 is a flow diagram illustrating a process for treating a water-based stream containing solids in accordance with embodiments of the present disclosure.

FIG. 4 is a flow diagram illustrating a process for treating a water-based stream containing solids in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION

Apparatus and methods are described herein for treating water-based streams containing solids, such as water-based drilling fluids, and for treating fluid streams, which may be water-based or non-aqueous, such as oil-based, containing solids. The apparatus described herein are suited for treating drilling fluids, which may be water-based or non-aqueous, for example oil-based. The methods and apparatus described herein can efficiently and effectively separate solids from a water-based fluid to yield a clean water stream and a compressed solid material, which may be a filter cake. Some methods and apparatus can treat 3 water-based fluids containing solids and non-aqueous fluids containing solids, for example oil-based fluids containing solids.

FIG. 1 is a process diagram illustrating a system and method of treating a water-based stream containing solids in accordance with at least one embodiment. In FIG. 1, a water-based stream is a fluid material 100, such as a drilling fluid or other fluid material that surfaces from an established well or a well being drilled into the earth. The fluid material 100 may carry solids dislodged by operation of a drill string and drill bit being extended into the earth. The solids dislodged by the drilling may be large, and at least some such solids may be removed using a bulk separator 101, which may be a shaker or other bulk solids removal unit. The fluid material 100 may be provided to the bulk separator 101 by any suitable means. In numerous embodiments, the bulk separator 101 can have an effluent 102 exiting the bulk separator 101 and can be generally described as a slurry, that is a fluid material consisting of fluidized solids in a liquid carrier. The system illustrated in FIG. 1 is an embodiment of a system for separating the solids from the effluent 102 of the bulk separator 101 (or the fluid material 100 if no bulk separator is used), rendering the solids into a convenient form, and yielding a clean liquid. It should be noted that in some embodiments of the system, a first portion 140 of the fluid material 100 may be routed to the bulk separator 101, while a second portion 144 is blended with the effluent 102, bypassing the bulk separator 101.

A slurry 104 derived from the effluent 102, or a mixture of the effluent 102 with a portion of the fluid material 100, is routed to a mixing vessel 106. In accordance with many embodiments, a mixing agent such as a flocculant agent 108 and/or a coagulant agent 110 are added to the mixing vessel 106, either separately or pre-blended, to form a mixture 112 in the mixing vessel 106. The flocculant agent 108 and the coagulant agent 110 cause agglomeration of solids in the mixture to enhance separation between solids and liquids. The flocculant agent 108 can be a conventional material, such as the FILTER FLOC flocculant agent available from SLB of Houston, Texas. In some embodiments the flocculant agent 108 may be any suitable agent. In various embodiments of the mixture 112, the coagulant agent 110 can be alum or an alum-based material or may be any suitable coagulant agent. It can be appreciated, that the flocculant agent 108 and/or the coagulant agent may be added via any suitable method. For example, some embodiments may have an integrated system for adding the agents to the slurry 104 that is in fluid communication with the mixing vessel 106. Other embodiments may have a manual system for adding the agents.

In accordance with some embodiments of the system, the mixture 112 may be transported for additional mixing to an in-line mixer 114, which may be a static or dynamic mixer. As should be appreciated, the bulk separator 101, the mixing vessel 106 and the in-line mixer 114 may be in fluid communication or connected with corresponding components of the system to allow for the movement of the fluid and/or solid materials used in the separation process.

The mixture 112 is provided to a drying module 116. The drying module 116 can have a number of different components that effectively separates the solids from the liquids by applying pressure and by enhancing separation using application of an electric field. In accordance with various embodiments, the drying module 116 may include, at least, a high efficiency separator 118, which may be a centrifuge or other separation device. The drying module 116 may also have an electro-osmotic filter press 120 to maximize separation of solids and liquid. In accordance with embodiments of the process, the high efficiency separator 118 receives the mixture 112 and yields an effluent liquid 122 free of solids. Wet solids 124 from the high efficiency separator 118 are routed to the electro-osmotic filter press 120, which yields a compressed solid material 126 and a solids-free liquid 128.

The electro-osmotic filter press uses mechanical pressure to squeeze liquid from the solids by compressing the solids against a filter cloth, belt, screening surface, perforated plate, or other separation surface 130, which may be a continuous medium such as a roll. The separation surface may be a consumable item. The electro-osmotic filter press also adds an electro-osmotic force to enhance water removal. Some embodiments can use a simple filter press where additional separation energy is not desired. The drying module 116 can use a transportation member 132 to transport the wet solids 124 from the high efficiency separator 118 to the press 120. For example, an angled conveyor, as shown in FIG. 1, can be the transportation member 132 to convey the wet solids 124 from an outlet of the high efficiency separator 118 to a receiving location of the press 120. The receiving location can be a location at which the wet solids 124 are processed by the press 120, or the receiving location can be a staging location from which the press 120 moves the wet solids 124 into a processing area. For example, as shown in FIG. 1, the transportation member 132 can deposit the wet solids at a receiving location of the separation surface 130, which can move the wet solids into a processing position, continuously or intermittently.

The effluent liquid 122 of the high efficiency separator 118 and the solids-free liquid 128 can be combined or separately routed to further uses. The compressed solid material 126 may be a cake (i.e. a filter cake) that is optimal for transportation. The compressed solid material 126 may be slightly damp after emerging from the drying module 116, and if desired the compressed solid material 126 can be further dried to form a dry solid. In any event, the method of FIG. 1, and apparatus described herein for performing the method, result in efficient and effective separation of solids from a water-based material containing solids, such as a drilling fluid.

A similar apparatus can be used to treat oil-based fluid materials containing solids, or other non-aqueous fluid material containing solids, as well as water-based fluid materials containing solids. FIG. 2 is a process diagram summarizing a method of treating water-based streams having solids and non-aqueous, for example oil-based, streams having solids. As in FIG. 1, a bulk separator 101 can optionally be used to remove larger solids from a fluid material 200, which can be oil-based or water-based. In the method of FIG. 2, a drying module 216 is used that is similar to the drying module 116 of FIG. 1, except that the drying module 216 has a diverter 204 that can divert wet solids from the high efficiency separator 118, when a non-aqueous or oil-based material is being treated, so that the wet solids are not routed to the electro-osmotic filter press 120. The diverter 204, which may be a gate, valve, conveyor with multiple outlets, reversible auger, or other flow diversion unit, can be provided between the high efficiency separator 118 and the electro-osmotic filter press 120 to divert solids derived from an oil-based stream, for example to a conveyor 202 that can remove the solids from the drying module 216. A controller 206 can be operatively coupled to the diverter 204 to control the diverter 204 to divert the solids to the conveyor system 202 or can direct the flow of material to the press 102. For example, the diverter 204 may have a sensor 205 in communication with the controller and the fluid stream that can detect whether the material being treated is a water-based material or a non-aqueous material. The sensor can signal the controller to operate or control the diverter 204 accordingly to direct the solids to the conveyor 202 or to the press 120.

The drying modules 116 and 216 may each include an optional separation enhancer 300. The separation enhancer 300 enhances operation of the high efficiency separator 118 to improve separation of solids from liquids. The separation enhancer 300 comprises a controller 302 that receives signals from a first density sensor 304, which is coupled to the mixture 112 being routed to the high efficiency separator 118, and from a second density sensor 306, which is coupled to the effluent liquid 122 recovered by the high efficiency separator 118. The controller 302 is operably coupled to the sensors 304 and 306 to receive signals that represent density of the fluid streams input to and output from the high efficiency separator 118. The controller 302 is also operably coupled to a pump 308, which provides a diluent stream 310 to the mixture 112 en route to the high efficiency separator 118. The controller 302 is configured to receive or determine a target density for the effluent liquid 122, to use the signals from the density sensors 304 and 306, to determine a control signal based on the target density and the signals from the sensors 304 and 306, and to send the control signal to the pump 308 to control a flow rate of the diluent 310 to the mixture 112. The diluent 310 may be water, an aqueous material, or an oil material depending on the nature of the mixture 112. The controller 302 may be configured to increase flow of the diluent 310 where signals from the second density sensor 306 indicate that density of the fluid effluent 122 is greater than the target density for the fluid effluent 122, and to reduce flow of the diluent 310 where the signals indicate that the density of the fluid effluent 122 is less than the target density. The controller 302 may also be configured to output no control signals if the density measured by the second density sensor 306 is within a target range, or within a tolerance range of the target density. It is believed that controlling the density of the mixture 112, or the liquid portion thereof, improves separation of solids from the liquid in the high efficiency separator 118 by improving movement of the solids within the liquid of the mixture 112. The density sensors 304 and 306 can be any suitable instruments. In one example, each of the density sensors 304 and 306 is a Coriolis instrument. In other cases, nuclear, ultrasound, microwave, or gravitic instruments can be used in addition to, or instead of, Coriolis instruments.

FIGS. 3 and 4 are flow diagrams that illustrate various embodiments of the process illustrated in embodiments of the system shown in FIGS. 1 and 2. For example, FIG. 3 illustrates an embodiment of the process where the system is configured to receive a fluid stream or effluent 320. The fluid stream is routed 321 to a mixing chamber where the flocculant agent and/or the coagulant agent are added (322 and 324). From there, the fluid stream or effluent and the agents are mixed 326 to form a mixture. The mixture can then be transitioned or moved 327 to a high efficiency separator. The high efficiency separator can then be used to create a solid stream 330 and a liquid stream 332 that are separate streams. In many embodiments, the liquid stream is a water-based or aqueous stream. In other embodiments, the fluid stream may not be fully water-based and therefore there may be another stream that is non-aqueous. After the solid stream and the liquid streams are created from the high efficiency separator, the solid stream can be routed to a drying module 333 where the stream can be further processed. As can be appreciated, the drying module can have a number of different components, similar to those described with respect to FIGS. 1 and 2 that can be used to further process the solid stream.

In many embodiments, the process within the drying module can have a various steps. Such as, the solid stream can be routed to a press 334. The press can be any suitable configuration such that it is configured to press or compress the solid stream to press out any residual fluid. This can then form a filter cake 338. In some embodiments, the drying module may also have additional processing equipment and steps to further dry the filter cake once it has been created.

As can be appreciated, the steps to process the drilling fluid can vary depending on the desired use and/or the desired outcome of the overall process. For example, FIG. 4 illustrates an embodiment of processing drilling fluid where the drilling fluid is received as a fluid stream 402. The fluid stream may contain a percentage of solids and liquids. In some embodiments, the liquids may be aqueous, non-aqueous, or a mixture of both. The fluid stream once received can be routed to a mixing chamber 403 where a flocculant agent is added 404 and/or a coagulant agent is added 406 to the fluid. There the agents and the fluid are then mixed to create a mixture 408. Once the mixture is created 408 it can be transferred 409 to a high efficiency separator where the liquids and the solids can be separated 410. The high efficiency separator is configured to separate or create two different streams. It will create a solid stream 412 and a liquid stream 412 during its process. The liquid stream can be evaluated or tested 416 using various sensors to determine the density 416 of the streams. If the density is the desired density then the liquid stream can be moved to any suitable location after the high efficiency separator. If the determined density 416 is not as required, then a pump can be used to pump diluent 415 back into the high efficiency separator to help further separate the solids 412 from the liquids in creating the solid and liquid streams.

Similarly, the created solid stream 412 can be tested or evaluated to determine if the stream is generally aqueous or non-aqueous. If the stream is non-aqueous then a diverted can be activated 430 by any number of controllers. The diverter can then divert 434 the solid stream to another suitable location for further processing of non-aqueous fluids. If the solid stream is aqueous then it can be routed to a press 420 where the press or compression mechanism will press 422 the solids to remove any residual liquid from the stream. Once pressed, the remaining solids can be formed into a filter cake 424. As can be appreciated, the press can utilize any suitable components such as an electro-osmotic filter press.

The preceding description has been presented with reference to present embodiments. Persons skilled in the art and technology to which this disclosure pertains will appreciate that alterations and changes in the described structures and methods of operation can be practiced without meaningfully departing from the principle, and scope of this present disclosure. Accordingly, the foregoing description should not be read as pertaining only to the precise structures described and shown in the accompanying drawings, but rather should be read as consistent with and as support for the following claims, which are to have their fullest and fairest scope.