CN105352788A - Hydraulic pressure supply control device used for hydraulic fracturing experiments, and experiment method thereof - Google Patents
Hydraulic pressure supply control device used for hydraulic fracturing experiments, and experiment method thereof Download PDFInfo
- Publication number
- CN105352788A CN105352788A CN201510814587.4A CN201510814587A CN105352788A CN 105352788 A CN105352788 A CN 105352788A CN 201510814587 A CN201510814587 A CN 201510814587A CN 105352788 A CN105352788 A CN 105352788A
- Authority
- CN
- China
- Prior art keywords
- hydraulic
- hydraulic pressure
- pump
- supply
- water guide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/02—Details
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
- G01N3/10—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces generated by pneumatic or hydraulic pressure
- G01N3/12—Pressure testing
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0014—Type of force applied
- G01N2203/0016—Tensile or compressive
- G01N2203/0019—Compressive
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/003—Generation of the force
- G01N2203/0042—Pneumatic or hydraulic means
- G01N2203/0048—Hydraulic means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0058—Kind of property studied
- G01N2203/006—Crack, flaws, fracture or rupture
- G01N2203/0067—Fracture or rupture
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/0202—Control of the test
Abstract
The invention relates to a hydraulic pressure supply control device used for hydraulic fracturing experiments, and an experiment method thereof. The hydraulic pressure supply control device comprises a diaphragm pump, a booster pump, and a water diversion steel cushion; the inlet end of the diaphragm pump is communicated with a water source pipeline; the outlet end of the diaphragm pump is communicated with a outlet end pipeline of the booster pump, and another outlet of the outlet end of the booster pump is communicated with a water diversion channel pipeline of the water diversion steel cushion via a high pressure pipeline; the water diversion steel cushion is detachably arranged on the surface of a test piece in a press machine; the booster pump is used for delivering high pressure liquid obtained via pressure increasing into the test piece via a water diversion channel. Operation of the hydraulic pressure supply control device is simple; continuous, stable, and accurate providing and recording of water pressure can be realized in a large pressure range. In hydraulic fracturing experiments, the hydraulic pressure supply control device can be connected with a single-shaft, a double-shaft, or a three-shaft press machine for test piece hydraulic fracturing; equipment connection and operation are simple; water pressure supply is stable; pressure value can be automatically controlled; detailed recording of pressure value and pressure change is realized; and experiment effect is excellent.
Description
Technical field
The present invention relates to a kind of hydraulic pressure apparatus for controlling of supply for Hydraulic Fracturing Experiment and test method thereof.
Background technology
Hydrofracturing is a kind of emerging technology grown up nearly decades, its essence is the characteristic utilizing fluid pressure transmission, injects fluid in porous medium, impels crack generate and expand in a certain direction.Since hydrofracturing adopts in the oil industry, the exploration of oil gas field and exploitation are played an important role.Since nineteen forty-seven, the U.S. carried out first time hydrofracturing, from theoretical research to field practice, all achieve larger development at home and abroad.Hydrofracturing simulation laboratory test is visual understanding fracture initiation and extension, explores the important means of fracture initiation and expansion mechanism, and in Practical Project, the effect better playing hydrofracturing technology is of great significance.
Hydrofracturing equipment conventional is at present large-scale three axle Hydraulic Fracturing Experiment systems, and this system is by large-scale true triaxial experiment frame, and Water hydraulic static pressure loading device, pressure plare, source of stable pressure, controller and other utility appliance are formed.This system advantage is the hydrofracturing be easy to realize under three axle confined pressures.Shortcoming is that equipment is complicated, and construction cost is high, takies physical space comparatively large, not easily realizes the large-scale popularization of Hydraulic Fracturing Experiment.The hydraulic pressure supply of our invention and control device, under the cooperation of existing single shaft, twin shaft and triaxial pressure machine, be easy to realize the Hydraulic Fracturing Experiment under single shaft, twin shaft and three axle confined pressures.At present at home in colleges and universities and scientific research institution, single shaft, twin shaft and triaxial pressure machine have been a large amount of normal experiment devices existed, and the hydraulic pressure that cooperations in, we invent supplies and control device, and the spread of Hydraulic Fracturing Experiment can be made to become a reality.
Summary of the invention
The object of the present invention is to provide a kind of hydraulic pressure apparatus for controlling of supply for Hydraulic Fracturing Experiment and test method thereof, this device can be connected with existing pressing machine is convenient, carry out Hydraulic Fracturing Tests, to solve the too high problem of existing Hydraulic Fracturing Experiment equipment cost.
In order to reach above-mentioned purpose, the present invention adopts following technical scheme:
For a hydraulic pressure apparatus for controlling of supply for Hydraulic Fracturing Experiment, comprise membrane pump, supercharge pump and water guide billet; The inlet end of described membrane pump is communicated with water supply line, the endpiece pipeline connection of membrane pump endpiece and described supercharge pump; Another outlet of the endpiece of described supercharge pump is by the conduit pipe pipeline connection of pressure duct and described water guide billet, the dismountable surface of test piece being placed in pressing machine of described water guide billet, the highly pressurised liquid after supercharging is sent to test specimen inside by described conduit pipe by described supercharge pump.
Utilize supercharge pump that the fracturing liquids such as water are forced into highly pressurised liquid, the requirement of Hydraulic Fracturing Tests to water under high pressure can not only be met, and structure is simple, can directly link on single shaft, twin shaft and three axle servo-pressing machines, with low cost, there is the scope of application widely.
The inlet end of described supercharge pump and the endpiece pipeline connection of air compressor.
The input end of described membrane pump and water tank pipeline connection.
The xsect of described water guide billet and the consistent size of described test specimen surface of contact.
The xsect of water guide billet and the consistent size of test specimen surface of contact, effectively can ensure the sealing effectiveness of liquid pressing.
Described conduit pipe is provided with bending in described water guide billet, and the inlet end of described conduit pipe departs from described water guide billet center position setpoint distance, and described conduit pipe endpiece is positioned at the center of described water guide billet.
The ingehious design of conduit pipe structure in water guide billet, the pressure-loaded of pressing machine and the Water hydraulic static pressure loading of hydraulic control device can be made to work simultaneously, can bear the high pressure of pressing machine, solving again traditional Water hydraulic static pressure loading device cannot independent of the technical barrier of pressing machine.
The upper and lower surface of described water guide billet is level and smooth.
The pressure limit that described supercharge pump provides is 0-300MPa.
Described pressure duct is provided with in order to observe and to record the intelligent instrument of hydraulic pressure-time data.
Described intelligent instrument is provided with to transmit recorded USB interface.
For a test method for the hydraulic pressure apparatus for controlling of supply of Hydraulic Fracturing Experiment, comprise the following steps:
Step 1: be connected with water source and air compressor pipeline respectively with the input end of supercharge pump by membrane pump, is connected the endpiece of described membrane pump with the endpiece pipeline of described supercharge pump;
Step 2: between loading termination water guide billet being placed in test specimen and pressing machine; The conduit pipe of described water guide billet is connected with the endpiece pipeline of described supercharge pump;
Step 3: start air compressor, for described supercharge pump provides initial gaseous tension, start supercharge pump and membrane pump afterwards, the pressure size of highly pressurised liquid is shown by intelligent instrument, highly pressurised liquid after supercharging is sent to test specimen inside by described conduit pipe by described supercharge pump, thus realizes described highly pressurised liquid and pressurize to the fracturing of test specimen; The unlatching order in no particular order of described air compressor, supercharge pump and membrane pump.
The invention has the beneficial effects as follows:
Described supercharge pump in 0-300MPa, can be stablized, accurately for equipment provides required pressure; The fracturing liquids such as water can be supplied to supercharge pump by membrane pump, the fracturing liquids such as water are become highly pressurised liquid; Air compressor can provide initial gaseous tension; Intelligent instrument can be observed and record hydraulic pressure-time data, and data can derive by USB device; High-pressure water pipe can transmit liquid, and connects this hydraulic pressure feedway and pressing machine; Water guide billet inside has conduit pipe highly pressurised liquid can be passed to test block inside, and backing plate upper and lower surface is level and smooth, pressing machine load can be loaded on test specimen and simulate confined pressure.
The present invention can stablize provides hydraulic pressure, is connected on pressing machine and just can carries out Hydraulic Fracturing Tests.Therefore the present invention can experimentally need, comparatively simple and easy, to carry out hydraulic pressure accurately supply, control and record.
The present invention is easy and simple to handle, in larger pressure range ability, can continue, stablizes, provide accurately and record hydraulic pressure.In Hydraulic Fracturing Tests, directly the present invention can be received on single shaft, twin shaft or triaxial pressure machine and carry out pressure break to test test specimen, connection and the operation of equipment are all very simple, hydraulic pressure supply is stable, pressure size can control voluntarily, and in detail, test effect is good for the record such as pressure value, change.
Accompanying drawing explanation
Fig. 1 is apparatus of the present invention and pressing machine equilibrium running diagram;
Fig. 2 is apparatus of the present invention schematic diagram;
Fig. 3 is the water guide billet axonometric drawing in apparatus of the present invention.
Marginal data: 1-water tank; 2-air compressor; 3-membrane pump; 4-supercharge pump; 5-intelligent instrument; 6-high-pressure conduit; 7-water guide billet; 8-rock sample; 9-pressing machine.
Embodiment
Below in conjunction with accompanying drawing, the present invention is described in detail.
Below in conjunction with the drawings and specific embodiments, the present invention is described in further details.
As shown in Figure 1-Figure 3, the supply of this hydraulic pressure and control device are preferably executed example and are comprised water tank 1, air compressor 2, membrane pump 3, supercharge pump 4, intelligent instrument 5, high-pressure conduit 6, water guide billet 7.Water tank 1 is connected with equipment body, the fracturing liquids such as water are provided, air compressor 2 is in the outside of equipment body, it is the compressed air source unit of native system, membrane pump 3 and supercharge pump 4 are positioned at the inside of equipment body, and intelligent instrument 5 is in equipment surface, and high-pressure conduit 6 is by each equipment connection, the effect of water guide billet 7 axis of pressing machine is loaded to pass to test block, makes highly pressurised liquid enter test test specimen inside by the conduit pipe of backing plate inside simultaneously and realize hydrofracturing.
When this preferred embodiment is applied to Hydraulic Fracturing Experiment, water tank 1 and air compressor 2 are external to respectively in membrane pump 3 and supercharge pump 4, high-pressure conduit 6 one end is connected to equipment body, one end connects water guide billet 7, and water guide billet 7 is placed between the loading termination of rock sample 8 and pressing machine 9.Adjustment switch, air compressor 2 is as compressed-air actuated pressure generator, initial gaseous tension is provided, this gaseous tension is sent in supercharge pump 4 by high-pressure conduit 6, open supercharge pump 4, increase this gaseous tension, promote the fracturing liquids such as the water that provides of membrane pump 3 simultaneously, hydraulic pressure size is measured by intelligent instrument 5 and is shown, through hole is had in water guide billet 7, through hole one end is connected with high-pressure conduit 6, the other end is connected with Hydraulic Fracturing Tests rock sample 8 hole, fracturing liquid can be made to enter test specimen inside smoothly, realization fracturing liquid is by test block pressure break and impel crack propagation, to study hydraulic fracture crack initiation, propagation law and mechanism.Water guide billet 7 upper and lower surface is smooth, the vertical load of pressing machine 9 can be delivered to test block surface to simulate vertical confined pressure, if desired simulate other two to confined pressure time, then to load other two axis axially applying pressing machinees.
To the above-mentioned explanation of the disclosed embodiments, professional and technical personnel in the field are realized or uses the present invention.To be apparent for those skilled in the art to the multiple amendment of embodiment, General Principle as defined herein can be without departing from the spirit or scope of the present invention, realize in other embodiments, the part be not described in detail, for prior art, do not repeat at this.Therefore, the present invention can not be restricted to these embodiments shown in this article, but will meet the widest scope consistent with principle disclosed herein and feature.
Claims (10)
1. for a hydraulic pressure apparatus for controlling of supply for Hydraulic Fracturing Experiment, it is characterized in that: comprise membrane pump, supercharge pump and water guide billet; The inlet end of described membrane pump is communicated with water supply line, the endpiece pipeline connection of membrane pump endpiece and described supercharge pump; Another outlet of the endpiece of described supercharge pump is by the conduit pipe pipeline connection of pressure duct and described water guide billet, the dismountable surface of test piece being placed in pressing machine of described water guide billet, the highly pressurised liquid after supercharging is sent to test specimen inside by described conduit pipe by described supercharge pump.
2. a kind of hydraulic pressure apparatus for controlling of supply for Hydraulic Fracturing Experiment according to claim 1, is characterized in that: the inlet end of described supercharge pump and the endpiece pipeline connection of air compressor.
3. a kind of hydraulic pressure apparatus for controlling of supply for Hydraulic Fracturing Experiment according to claim 1, is characterized in that: the input end of described membrane pump and water tank pipeline connection.
4. a kind of hydraulic pressure apparatus for controlling of supply for Hydraulic Fracturing Experiment according to claim 1, is characterized in that: the xsect of described water guide billet and the consistent size of described test specimen surface of contact.
5. a kind of hydraulic pressure apparatus for controlling of supply for Hydraulic Fracturing Experiment according to claim 1, it is characterized in that: described conduit pipe is provided with bending in described water guide billet, the inlet end of described conduit pipe departs from described water guide billet center position setpoint distance, and described conduit pipe endpiece is positioned at the center of described water guide billet.
6. a kind of hydraulic pressure apparatus for controlling of supply for Hydraulic Fracturing Experiment according to claim 1, is characterized in that: the upper and lower surface of described water guide billet is level and smooth.
7. a kind of hydraulic pressure apparatus for controlling of supply for Hydraulic Fracturing Experiment according to claim 1, is characterized in that: the pressure limit that described supercharge pump provides is 0-300MPa.
8. a kind of hydraulic pressure apparatus for controlling of supply for Hydraulic Fracturing Experiment according to claim 1, is characterized in that: described pressure duct is provided with in order to observe and to record the intelligent instrument of hydraulic pressure-time data.
9. a kind of hydraulic pressure apparatus for controlling of supply for Hydraulic Fracturing Experiment according to claim 8, is characterized in that: described intelligent instrument is provided with to transmit recorded USB interface.
10., for a test method for the hydraulic pressure apparatus for controlling of supply of Hydraulic Fracturing Experiment, it is characterized in that, comprise the following steps:
Step 1: be connected with water source and air compressor pipeline respectively with the input end of supercharge pump by membrane pump, is connected the endpiece of described membrane pump with the endpiece pipeline of described supercharge pump;
Step 2: between loading termination water guide billet being placed in test specimen and pressing machine; The conduit pipe of described water guide billet is connected with the endpiece pipeline of described supercharge pump;
Step 3: start air compressor, for described supercharge pump provides initial gaseous tension, start supercharge pump and membrane pump, the pressure size of highly pressurised liquid is shown by intelligent instrument, highly pressurised liquid after supercharging is sent to test specimen inside by described conduit pipe by described supercharge pump, thus realizes described highly pressurised liquid and pressurize to the fracturing of test specimen; The unlatching order in no particular order of described air compressor, supercharge pump and membrane pump.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510814587.4A CN105352788B (en) | 2015-11-20 | 2015-11-20 | A kind of hydraulic pressure apparatus for controlling of supply and its test method for Hydraulic Fracturing Experiment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510814587.4A CN105352788B (en) | 2015-11-20 | 2015-11-20 | A kind of hydraulic pressure apparatus for controlling of supply and its test method for Hydraulic Fracturing Experiment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105352788A true CN105352788A (en) | 2016-02-24 |
| CN105352788B CN105352788B (en) | 2018-04-20 |
Family
ID=55328795
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510814587.4A Active CN105352788B (en) | 2015-11-20 | 2015-11-20 | A kind of hydraulic pressure apparatus for controlling of supply and its test method for Hydraulic Fracturing Experiment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105352788B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108760515A (en) * | 2018-04-27 | 2018-11-06 | 中国石油天然气股份有限公司 | Loading stress tests the experimental system and method for fracture height extension |
| CN111141599A (en) * | 2020-03-09 | 2020-05-12 | 山东科技大学 | True triaxial hydraulic fracturing test method capable of adjusting fracturing hole direction |
| CN112665992A (en) * | 2020-12-17 | 2021-04-16 | 山东大学 | Pulse static pressure combined hydraulic fracturing method, test system and use method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4648810A (en) * | 1981-10-17 | 1987-03-10 | Barmag Barmer Maschinenfabrik Ag | Control apparatus for a positive displacement reciprocating pump |
| CN201706202U (en) * | 2010-02-01 | 2011-01-12 | 广东神洲化学工业有限公司 | Liquid material conveying device |
| CN203532382U (en) * | 2013-10-11 | 2014-04-09 | 中国地震局地壳应力研究所 | High-pressure fluid control system for hydraulic fracture in-situ stress measurement |
| CN103776703A (en) * | 2014-01-24 | 2014-05-07 | 山东大学 | Hydro-fracturing water injection loading device based on rock-like resin sample and test method |
| CN205103091U (en) * | 2015-11-20 | 2016-03-23 | 山东大学 | A water pressure supply control device for hydrofracturing experiment |
-
2015
- 2015-11-20 CN CN201510814587.4A patent/CN105352788B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4648810A (en) * | 1981-10-17 | 1987-03-10 | Barmag Barmer Maschinenfabrik Ag | Control apparatus for a positive displacement reciprocating pump |
| CN201706202U (en) * | 2010-02-01 | 2011-01-12 | 广东神洲化学工业有限公司 | Liquid material conveying device |
| CN203532382U (en) * | 2013-10-11 | 2014-04-09 | 中国地震局地壳应力研究所 | High-pressure fluid control system for hydraulic fracture in-situ stress measurement |
| CN103776703A (en) * | 2014-01-24 | 2014-05-07 | 山东大学 | Hydro-fracturing water injection loading device based on rock-like resin sample and test method |
| CN205103091U (en) * | 2015-11-20 | 2016-03-23 | 山东大学 | A water pressure supply control device for hydrofracturing experiment |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108760515A (en) * | 2018-04-27 | 2018-11-06 | 中国石油天然气股份有限公司 | Loading stress tests the experimental system and method for fracture height extension |
| CN108760515B (en) * | 2018-04-27 | 2020-09-08 | 中国石油天然气股份有限公司 | Experimental system and method for testing crack height expansion by loading stress |
| CN111141599A (en) * | 2020-03-09 | 2020-05-12 | 山东科技大学 | True triaxial hydraulic fracturing test method capable of adjusting fracturing hole direction |
| CN112665992A (en) * | 2020-12-17 | 2021-04-16 | 山东大学 | Pulse static pressure combined hydraulic fracturing method, test system and use method thereof |
| CN112665992B (en) * | 2020-12-17 | 2023-06-20 | 山东大学 | Pulse static pressure combined hydraulic fracturing method, test system and use method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105352788B (en) | 2018-04-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN205103091U (en) | A water pressure supply control device for hydrofracturing experiment | |
| CN110487697B (en) | Supercritical carbon dioxide injection coal rock mechanical property test and fracturing experiment device | |
| CN107567547B (en) | System and method for the shared manifold with integrated hydraulic energy transfer system | |
| CN104596905B (en) | Device and method for measuring permeability of rock in fracturing process | |
| CN100445741C (en) | Intelligent high-temperature high-voltage experimental instrument for dynamic leak stopping evaluation | |
| CN105628501B (en) | True triaxial hydrofracturing rock mechanics testing system | |
| CN105352788A (en) | Hydraulic pressure supply control device used for hydraulic fracturing experiments, and experiment method thereof | |
| CN108333098A (en) | Shale gas reservoir micro-fractures high-temperature and high-pressure visual air water two phase fluid flow experimental provision | |
| CN103375155B (en) | The linear physical simulation system of heavy crude reservoir thermal recovery | |
| CN102297809A (en) | Low-temperature fatigue test system of corrugated pipe | |
| CN106337677A (en) | Gas-water two-phase flow guide capability testing system of shale gas pressure crack net and testing method | |
| CN201794580U (en) | High-temperature high-pressure plugging simulation testing device for drilling fluid | |
| CN105332683B (en) | Fracturing experiments device and method | |
| CN105628526B (en) | Dynamic loading hydraulic fracturing rock mechanical test system | |
| WO2018166294A1 (en) | Three-dimensional physical simulation experiment device for microbial enhanced oil recovery | |
| CN205941297U (en) | A permeability rapid measurement device for high density rock | |
| CN207570982U (en) | A kind of true triaxial Seepage Experiment structure for applying non-uniform load | |
| CN111257540B (en) | Supercritical CO evaluation2Experimental method and device for full-period fracturing energy storage flow-back effect | |
| CN201943703U (en) | Imitated coal bed mining device | |
| CN107907467A (en) | A kind of true triaxial seepage experimental apparatus for applying non-uniform load | |
| CN203322734U (en) | Prying device for standby natural gas sources | |
| CN204556178U (en) | A kind of subsurface safety valve test macro | |
| CN104422614A (en) | Pipeline external pressure test device | |
| CN116429588A (en) | Coal rock mass fracturing modification and effect evaluation test system and method thereof | |
| CN201522362U (en) | Soft packaging bag pressure safety detector |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |