Patent Application
20240117690
Various embodiments relate generally to a flocculant pretreatment process before reintroducing contaminated drilling fluids to a drilling pit used for drilling purposes.
Boreholes are narrow shafts bored in the ground. Boreholes may, for example, be either vertical or horizontal. A borehole may, for example, be constructed to extract water. A borehole may, for example, be constructed to drill petroleum. A bore hole may, for example, be constructed to drill for natural gas. Boreholes may, for example, be used in a geotechnical investigation. Boreholes may, for example, be used in an environmental site assessment. Boreholes may, for example, be used in mineral explorations. Boreholes may, for example, be used for temperature measurement. Boreholes may, for example, as a pilot hole for installing piers or underground utilities. Boreholes may, for example, be used in geothermal installations. Boreholes may, for example, be used for underground storage of unwanted substances (storage and/or CO2 capture projects).
Drilling fluid, also known as drilling mud, is used to aid the drilling of boreholes. Often drilling fluid is used while drilling oil and natural gas wells. Drilling fluids may, for example, be used on exploration drilling rigs. Drilling fluids may, for example, be used for simpler boreholes, such as water wells.
Drilling fluids may, for example, include water-based muds (WBs). Water based muds may, for example, be dispersed and non-dispersed. Drilling fluids may, for example, include non-aqueous muds. Non-aqueous mud may, for example, be called oil-based muds (OBs). Drilling fluids may, for example, include gaseous drilling fluid. Gaseous drilling fluids may, for example, include a wide range of gases. Drilling fluids may, for example, include appropriate polymer and clay additives for drilling various oil and gas formations.
Apparatus and associated methods relate to a Drilling Return Flowline Continuous Agitation Flocculant Metering Dispenser in a flowline. The metering device includes a pump and a reservoir. The reservoir contains flocculant (e.g., a polymeric drilling fluid, MF55 drilling fluid) in a suspension (e.g., water). The pump maintains a continuous circulation of the flocculant suspension through the pump. A first outlet meters a predetermined flow rate of the flocculant suspension into a flowline in a drilling reserve pit. The remainder of the flocculant suspension is returned to the reservoir through a first outlet. A valve on the first outlet and a second valve on the second outlet allows an adjustment of the return and metering outlet streams. The metered flow allows the flocculant into the flowline such that the drilling fluid is constantly mixed with the flocculant suspension as the drilling fluid is returned to the drilling reserve pit.
Some embodiments may, for example, be configured such that the continuous circulation keeps the flocculant agitated and in suspension to prevent settling out.
Accordingly, solids in the used drilling fluid may advantageously be brought into substantially uniform contact with the flocculant suspension such that the solids are bound and settle out (e.g., flocculation). A drilling rig supplied from the drilling reserve pit may advantageously operate with less solids, reducing friction, which may advantageously increase drilling speeds.
The details of various embodiments are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description and drawings, and from the claims.
Appendix A depicts an exemplary drilling return flowline continuous agitation flocculant metering dispenser.
To aid understanding, this document is organized as follows. First, to help introduce discussion of various embodiments, a system to pretreat the contaminated drilling fluids is introduced with reference to
Drilling fluids 110 in various embodiments may serve many different functions including, by way of example and not limitation, be used to control formation pressures, to remove subterranean cuttings from a wellbore, to seal permeable formations encountered while drilling, to cool downhole tools, to lubricate downhole tools, to maintain wellbore stability, to transmit hydraulic energy to downhole tools, or some combination thereof. In some implementations, by way of example and not limitation, downhole tools may include a drilling bit and/or other drilling equipment.
Drilling fluids 110 may be pumped from the drilling pit 105 through a supply line 115. The supply line 115 may, for example, include a pipe, a tubing, a hose structure, or some combination thereof.
In the depicted illustrative example 100, the supply line 115 connects to the well 120 which may be used to, for example, harvest petroleum oil hydrocarbons. The well 120 may be used, for example, to support a drill stem 125. The drill stem 125 may be used, for example, to transport drilling fluids 110, to support axial loads, and/or to support torsional loads. The drill stem 125 may be used to create a wellbore 130 to drill beneath a grounds surface. The wellbore 130 may, for example, include a hole that is drilled to aid in the exploration and recovery of natural resources including but not limited to oil, gas, water, or some combinations thereof.
The wellbore 130 and the drill stem 125 in the depicted example 100 are protected by an exterior casing 130. The exterior casing, for example, may be larger in diameter than the drill stem 125, may be longer in length than the drill stem 125, and/or may be used to line the wellbore 130. An exterior casing 135 may be used to offer support to prevent the wellbore 130 from collapsing. The exterior casing 135 may, for example, be used to protect the drill stem 125. The exterior casing also may, for example, be used to protect the drilling fluids 105 from contaminants, as the drilling fluids are used to lubricate the drilling stem 125 and a drill bit 125a connected to a bottom of the drilling stem 125. The drill bit 125a, may be attached to the drill stem 125 to drill a subterranean surface 140.
The drilling fluids 110 may, for example, lubricate the drill bit 125a as the drill bit 125a drills into a subterranean formation 140. A drill bit 125a may be used, for example, to reduce the torsional forces required to drill the subterranean formation 140. As the drill bit 125a drills into the subterranean formation 140, the drilling fluids 110 may become contaminated with drill cuttings from the subterranean formation 140 to create a contaminated drilling fluids 110a. Drill cuttings may comprise of subterranean particles generated by the drilling of the subterranean formation 140. Subterranean particles may, for example, be small pieces of rock varying in size and texture from fine silt to gravel. Drilling fluids may, for example but is not limited, may to become contaminated from subterranean particles, subterranean fluids, subterranean gases, or combinations thereof located in the subterranean formation 140. For example, subterranean particles may contaminate the drilling fluids making it no longer suited for drilling purposes without further treatment to remove the subterranean particles.
The contaminated drilling fluids 110a may be pumped from the drill bit 125a to a return line 145 which may, for example, be used to transport the contaminated drilling fluids 110a to the drilling pit 105. The return line 145 may, for example, comprise of a pipe, a tubing, hose structure, or some combinations thereof. The return line 145 may be connected to a two-way valve 150. The two way-valve connection may be used to pretreat the contaminated drilling fluids 110a with a flocculant fluid 160 before being pumped to the drilling pit 105. The two-way valve 150 may for example be connected by means of a pipe, tube, hose structure or combination thereof to a Continuous Agitation Flocculant Metering Dispenser (CAFMD) 155, which may be used to mix the flocculant fluid 160 with the contaminated drilling fluids 110a. The CAFMD 155 may, for example, be connected to a series of valves, flocculant containers, and pumps, and combinations thereof.
The amount of flocculant fluid disbursed may, for example, be dependent on parameters such as the brand of flocculant fluid, the viscosity of the contaminated drilling fluids 110a, the density of the contaminated fluid, the power consumed by the pump to generate flow, the structural integrity of the return line 145, the diameter of the return line 145, or some combination thereof.
As the flocculant fluid 160 mixes with the contaminated drilling fluids 110a in a flocculant pretreatment process 165, the rock cuttings and other contaminants from the subterranean formation 140 in the contaminated drilling fluids 110a may begin to clump and aggregate creating larger particles 170. The flocculant pretreatment process 165, may, for example, be used to maximize the contact and mixing between the contaminated drilling fluids 110a and the flocculant fluid 160 to create larger particles 170 in a flocculent suspension before the pretreated contaminated drilling fluids 110b reenter the drilling pit 105.
As depicted in the exemplary illustrative use case scenario 100, the larger particles 170 created in the flocculant pretreatment process 165 may outflow from the two-way valve 150 as a pretreated contaminated drilling fluids 110b. The pretreated contaminated drilling fluids 110b may, for example, be outflown to drilling pit 105 where the contaminated drilling fluids may, for example, separate and sink to a bottom 175 of the drilling pit 105. The larger particles 170 containing contaminants may, for example, advantageously facilitate less costly and faster removal of contaminants once the larger particles 170 are reintroduced into the drilling pit 105.
In the depicted exemplary system 200, a drilling pit 205 acts as a reservoir for drilling fluids 210. The drilling fluids 210 may be pumped to a well 215. The well, may for example, be used to pump drilling fluids 210 below the ground and also collect contaminated drilling fluids 210a from the drilling process.
The contaminated drilling fluids 210a may be transported to a pretreatment process location 255. At the pretreatment process location 255, flocculant from a flocculant storage container 250 may be dispensed by means of a flocculant dispenser 225 (e.g., the CAFMD 155). The flocculant dispenser may release flocculant through a dispenser valve 230. The dispenser valve 230 may, for example, be connected to a pump 235. The pump 235 may, for example, be used to pump flocculant from the flocculant storage container 250 to the dispenser valve 230. The pump 235 may, for example, be connected to the flocculant storage container 250 by a suction valve 245 that transports the flocculant to the pump 235. The pump 235 may, for example, pump excess flocculant back into the flocculant storage container 250 through the connection of a receiver valve 240. The suction valve 245, the dispenser valve 230, the receiver valve 240, and combination thereof, may be set to various flow rates, for example, to control the amount of flocculant dispersed from the flocculant dispenser 225 into the pretreatment process location 255.
Controlling the amount of flocculant dispensed at the pretreatment process location 255, may, for example, control properties which may contribute to the flow speed of a pretreated contaminated drilling fluids 220b, such as, for example, the viscosity of the contaminated drilling fluids 110a, density of the contaminated drilling fluids 110a, and combination thereof. The density of the fluid may be determined by the mass of the fluid contained in a specific volume.
In various embodiments, the viscosity of the fluid may be determined by various parameters. For example, viscosity may be determined based on a force applied to the fluid (e.g., by a drilling pump) to produce a given flow. In some examples, viscosity may be determined based on a cross-sectional area that the fluid flows through. Viscosity may, for example, be determined in some examples based on temperature. The viscosity may, for example, be determined based on a shear rate of deformation.
In some implementations, by way of example and not limitation, the flow meter 260 may be configured as a laser meter. In some implementations, the flow meter 260 may, for example, be configured as an electronic meter. In some implementations, the flow meter 260 may include an ultrasonic meter. In some embodiments, the flow meter 260 may be configured as a mechanical meter (e.g., sensing changes in motion and/or position of a spinning and/or displaceable element responsive to flow).
In some implementations, an electronic control system (not shown) may be operably coupled to the flow meter. The control system may, for example, read data from the flow meter and make automatic changes to valves based on the flow meter. For example, the control system may maintain a predetermined flow rate. For example, the control system may be configured to maintain a predetermined flocculant concentration in the dispensed flow stream. In some implementations, the control system may maintain a predetermined relationship between at least one attribute of the dispensed flocculant stream and at least one other attribute (e.g., composition of the flow stream in the return line 145, contaminants present in the return line 145, flow rate in the return line 145, flocculant in the reservoir 150).
As depicted, the flocculant dispenser 225 includes a venturi mixer 265. In this example, the venturi mixer 265 is configured to mix a flocculant from an inlet 266 into a return line from the pump 235 to the flocculant storage container 250. For example, the flocculant storage container 250 may be filled with a pre-mixed flocculant. In some examples, the flocculant storage container 250 may be replenished with an unmixed (e.g., concentrated, dry, powdered, granular) flocculant. For example, unmixed flocculant may be supplied at the inlet 266, and the venturi mixer 265 may draw the unmixed flocculant in through the inlet 266, mixing it with fluid (e.g., water) in the return line, thus replenishing the flocculant storage container 250. In some implementations, the flocculant storage container 250 may, for example, be bypassed and/or omitted.
For example, some implementations may be configured such that the flocculant storage container 250 may be selectively bypassed (e.g., by an operator, by an electronic control unit). Some embodiments may, for example, be configured (e.g., by a valve, by a plug) such that the inlet 266 may be selectively (e.g., by an operator, by an electronic control unit) in fluid communication with the return line. For example, the venturi mixer 265 may be enabled (e.g., unplugged, selectively operated into a flow stream) when additional flocculant is needed and/or an unmixed source is to be used for flocculant.
In some implementations, for example, unmixed (e.g., dry powder) flocculant may be used to enable use of a particular flocculant (e.g., cationic, anionic). For example, a premixed flocculant may be only available in an anionic formulation. A cationic flocculant may be desired and/or required (e.g., based on contaminants present), but may be available only in a dry powder form. Accordingly, the venturi mixer 265 may be used to draw the dry powder into a fluid stream for dispensing through the dispenser valve 230. In some examples, costs may advantageously be reduced (e.g., by 80% or more) by using unmixed dry powder polymer flocculant vs premixed polymer flocculant. In some implementations, transport difficulties and/or costs may be reduced by using a concentrated flocculant and mixing it in the flocculant dispenser 225.
The flocculant dispenser includes a bypass valve 250a. The bypass valve may, for example, be used to switch between two types of flocculent. The bypass valve 250a connects to a secondary flocculant chamber 250a. The second flocculant chamber is configured such that it mixes the second type of flocculant contained within chamber with receiving fluid. The flocculant mixture is then directed to the return line to treat the line through an exit line 251.
In response to receiving the contaminated drilling fluids 110a, a suction valve 245 may be operated to set flow rate Q1 in step 310. Flow rate Q1 may, for example, be used to transport the flocculant particles from the flocculant storage container 250 to the pump 235 in the depicted exemplary system 200.
In response to flow rate Q1, a dispenser valve may be operated to set flow rate Q2 in step 315. Flow rate Q2 may, for example, dispense flocculant to be mixed into the contaminated drilling fluids 110a in the flocculant pretreatment process 165 depicted in the exemplary illustrative use case scenario 100.
In response to flow rate Q2, the receiver valve may be operated to set flow rate Q3 in step 315. Flow rate Q3 may, for example, be used to control the amount of flocculant pumped back into the flocculant storage container 250 from the receiver valve 240, as depicted in the depicted exemplary system 200. The pump 235, for example, may be used to dispense the flocculent fluids to pretreat the contaminated drilling fluids.
In response to and/or in correspondence to setting the dispenser valve, receiver valve, suction valve, or combination thereof, the pump may be used to dispense flocculant stream in step 320 from the Q2 dispenser valve.
In response to the operation of the pump, a determination of whether the output suspension is greater than a predetermined density or viscosity criterion may be made in step 330. If the output suspension is greater than a predetermined density or viscosity criterion the dispenser valve may, for example, be set to reduce the amount of flocculant dispensed from the CAFMD 155 as depicted in the exemplary illustrative use case scenario 100.
Density parameters may be determined, by way of example and not limitation, by an amount of mass contained within a specific amount of volume. The viscosity of the fluid may be determined by various parameters, such as disclosed at least with reference to
In response or in conjunction to step 330, it is determined whether the output suspension is greater than a predetermined flocculent concentration. If the flocculant suspension is not greater than a predetermined flocculant concentration ratio, the operator valve may be operated to increase the flow rate Q2 into the pretreatment location. If the output suspension becomes greater than a predetermined flocculant concentration ratio greater, then the pump may be operated to maintain the desired flocculent concentration.
The flocculant concentration may, for example, be increased to cause the contaminants within the contaminated drilling fluids to clump together. The drill shavings and subterranean particles may, for example, clump together until a point where it would be undesirable for the pretreated contaminated fluid to become more viscous. Increasing the viscosity of the contaminated drilling fluid beyond a certain point may, for example, cause the pump to stall, cause a leak in the return line, reduce drilling speed, or some combination thereof.
In some implementations, the flocculant concentration ratio may, for example, be selected to maximize the solid removal speed from the return line 145 depicted in the exemplary illustrative use case scenario 100.
In some embodiments, the flocculent concentration ratio may, for example, be selected to create larger clumps of subterranean particles that can be later be removed. Larger clumps may, for example, advantageously be more thoroughly removed from the drilling fluid. Cleaner drilling fluid may, for example, advantageously enable faster and/or more efficient drilling speeds. Faster and more efficient drilling speeds may, for example, be enabled because the contaminated drilling fluids 110a would need less treatment at the drilling pit 105, because the contaminated drilling fluid 110a has already been pretreated with flocculant fluid 160 in the flocculent suspension.
As an illustrative example, the flocculant may include a polymer suspension. The solvent may, for example, include water. The flocculant to solvent ratio may, for example, be selected based on a particulate flocculant, a particulate solvent, a particulate pump (e.g., pump 235), a particular drilling environment (e.g., subterranean formation 140), a particular drilling rig, a particular bottom hole assembly, or some combination thereof. For example, in the illustrative embodiment depicted in
The flocculant suspension may, by way of example and not limitation, include a ratio of between 1:2 to 1:25 flocculant to solvent. In the illustrative example, a ratio greater than 1:25 may, by way of example and not limitation, cause the flocculant to fall out of suspension and/or cause the suspension to exceed a target maximum viscosity. A flocculent ratio lower than 1:2 may, for example, cause the suspension to not sufficiently contact the solids in the flow line. In a test using the exemplary CAFMD 400 with the previously described illustrative flocculant suspension, drilling pump pressures were lowered by substantially 300 pounds per square inch (PSI). For example, without being bound to a particular theory, the automatic and continuous dispensing of the continuously agitated flocculant suspension into the flowline is believed to have increased flocculant contact (e.g., due to increased local concentration in the flowline) rather than being dilutely distributed in the entire reservoir pit) with solid contaminants suspending in the drilling fluid. Increased contact is believed to increase binding of the flocculant with the solids and so aggregation of the contaminants. Increased aggregation is believed to cause more effective removal (e.g., settling out, mechanical removal/separation) before recycling of the drilling fluid into the drilling rig. Accordingly, the drilling fluid being recycled into the drilling rig had a lower friction, reducing the pressure in the pump. In the test, the reduced friction enabled faster drilling of the well, enabling the well drilling to be completed ahead of schedule.
Although various embodiments have been described with reference to the figures, other embodiments are possible.
Although an exemplary system has been described with reference to FIGS., other implementations may be deployed in other industrial, scientific, medical, commercial, and/or residential applications. Some embodiments of the drilling return flowline continuous agitation flocculant metering dispenser may, for example, be used in oil and gas refineries. The drilling return flowline continuous agitation flocculant metering dispenser may, for example, be used at drilling sites for liquids and gases (e.g., natural gas, petroleum, water). The drilling return flowline continuous agitation flocculant metering dispenser may, be used to drill holes used for CO2 capture or storage.
A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made. For example, advantageous results may be achieved if the steps of the disclosed techniques were performed in a different sequence, or if components of the disclosed systems were combined in a different manner, or if the components were supplemented with other components. Accordingly, other implementations are contemplated.
This application also claims the benefit of U.S. Provisional Application Ser. No. 63/379,091, titled “Drilling Return Flowline Continuous Agitation Flocculant Metering Dispenser,” filed by Freeman Pump Solutions, Inc, et al., on 10/11/2023.
| Number | Date | Country | |
|---|---|---|---|
| 63379091 | Oct 2022 | US |
