Detailed Description
The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.
The invention provides a drilling fluid in a first aspect, wherein the drilling fluid comprises the following components by taking the total amount of the drilling fluid as a reference: 2-4 wt% of bentonite, 0.4-0.6 wt% of tackifier, 4-6 wt% of filtrate reducer, 1.7-5 wt% of inhibitor, 1-5 wt% of plugging anti-collapse agent, 1-3 wt% of lubricant, 0.4-1 wt% of waterproof locking agent, 0-4 wt% of compact pressure-bearing temporary plugging agent, 0-20 wt% of weighting agent and 51.4-89.5 wt% of water.
In the invention, the total amount of the drilling fluid is taken as a reference, and the compact pressure-bearing temporary plugging agent accounts for 2-4 wt% of the drilling fluid.
In the invention, the density of the drilling fluid is 1.05-1.15g/cm3。
In the invention, the compact pressure-bearing temporary plugging agent is preferably 2-4 wt%, and the drilling fluid prepared under the condition is more suitable for a fractured compact sandstone reservoir, so that the protection of the drilling fluid system on a compact sandstone matrix and a microcrack is improved, the mechanical drilling speed is favorably improved, and the friction resistance is reduced.
In the invention, based on the total amount of the compact pressure-bearing temporary plugging agent, the compact pressure-bearing temporary plugging agent comprises: 60-70 wt% of calcium carbonate, 20-30 wt% of high acid soluble fiber and 5-20 wt% of ultra-low permeability treatment agent.
Preferably, the calcium carbonate has a particle size of 40-400 mesh.
The selection of calcium carbonate is not particularly limited as long as the particle size of calcium carbonate is 40 to 400 mesh, preferably 100-300 mesh, within which the calcium carbonate is more sufficiently mixed with other components. The particle size of the calcium carbonate is graded, and for example, the particle size satisfies D50-187.9 μm and D90-365.9 μm.
In the invention, the length of the high acid soluble fiber is 20-40 μm, and the diameter is 0.5-2 μm.
The selection of the high acid-soluble fiber is not particularly limited, and the above conditions are satisfied, and for example, SDCF-1, manufacturer: shandong province Yingshi Dai Innovation Co., Ltd.
In the invention, the grain diameter of the ultra-low permeation treating agent is 80-2000 meshes.
The ultra-low permeability treatment agent is purchased from stone major innovation ltd of Dongying city under the trademark SDN-1, and the particle size distribution of the ultra-low permeability treatment agent can be D50-66.91 μm and D90-182.2 μm. The ultra-low permeability treatment agent in the particle size range is more uniformly mixed with calcium carbonate and high acid soluble fiber, and can effectively prevent fluid from invading stratum.
The weighting agent is used for adjusting the density of the drilling fluid, the selection of the weighting agent is not particularly limited, and limestone can be used.
In the invention, the selection of the bentonite is not particularly limited, and the bentonite meets the quality index of the bentonite for drilling mud in GB/T20973, and comprises the filtration loss of less than or equal to 15cm3The reading of the viscometer is more than or equal to 30 r/min, the yield value/plastic viscosity is less than or equal to 3, and the mass fraction of the 75 mu m screen residue is less than or equal to 4 percent. The tackifier is not particularly limited, and polyanionic cellulose, low-viscosity carboxymethyl cellulose and hydroxyethyl cellulose can be selected, so that the filtration loss is less than or equal to 10 mL.
In the invention, the fluid loss additive comprises the following components by taking the total amount of the drilling fluid as a reference: 2-3 wt% of high-temperature high-pressure fluid loss additive and 2-3 wt% of lignite resin.
The selection of the high-temperature high-pressure fluid loss additive is not particularly limited, and examples thereof include SD201 and SD 202. The selection of the lignite resin is not particularly limited, and the lignite resin having a trade name of SPNH may be selected so that the apparent viscosity is not more than 12mPa · s. The high-temperature high-pressure fluid loss additive is matched with the lignite resin, so that the fluid loss reduction effect is good, and the performance is stable.
In the present invention, the inhibitor includes potassium salts and ammonium salts; preferably, the potassium salt is an organic potassium salt and/or an inorganic potassium salt, and the ammonium salt is an organic ammonium salt and/or an inorganic ammonium salt.
The inhibitor adopts a mode of compounding potassium salt and ammonium salt, and preferably the addition amount of the potassium salt is 1.2-3.5 wt% and the addition amount of the ammonium salt is 0.5-1.5 wt% based on the total amount of the inhibitor. Wherein the potassium salt can be selected from potassium chloride, potassium carbonate, polyacrylamide potassium salt, and potassium polyacrylate. The ammonium salt can be selected from dodecyl dimethyl benzyl ammonium chloride and hydrolyzed polyacrylonitrile ammonium salt.
According to the invention, the plugging anti-collapse agent is high-acid-soluble sulfonated asphalt, the softening point of the high-acid-soluble sulfonated asphalt is more than or equal to 80 ℃, and the acid solubility is more than or equal to 90%.
The selection of the high acid-soluble sulfonated asphalt is not particularly limited, and may satisfy the specification that the softening point is not less than 80 ℃ and the acid solubility is not less than 90%, and may be FF-1, for example. The plugging anti-collapse agent is matched with the inhibitor, so that the high-temperature and high-pressure filtration loss of the drilling fluid is reduced, and the anti-collapse performance is improved.
In the invention, the lubricant is graphite, the particle size of the graphite is 325-10000 meshes, and the reduction rate of the lubricating coefficient is more than or equal to 45%.
Graphite can be artificial graphite, cubic graphite, scale graphite or microcrystalline graphite, and the particle size of graphite can be 325-type 10000 meshes, preferably 325-type 600 meshes, and in this particle size range, graphite is as the lubricant, can with other component intensive mixing, the coefficient of lubrication reduction is more than or equal to 45%.
In the present invention, the selection of the water-blocking agent is not particularly limited as long as the specification is satisfied with a density of 0.8 to 1.0g/cm3The surface tension of the 1% aqueous solution is less than or equal to 28mN/m, and can be SDFS-1, manufacturer: shandong province Yingshi Dai Innovation Co., Ltd.
The second aspect of the invention provides an application of the drilling fluid in tight sandstone reservoirs, preferably fractured tight sandstone reservoirs.
The drilling fluid prepared by the method can reduce the water lock damage of a compact sandstone matrix reservoir, has better anti-collapse performance and water lock prevention performance aiming at a fractured compact sandstone reservoir, and has obvious reservoir protection effect. Aiming at the fractured compact sandstone reservoir, the addition amount of the compact pressure-bearing temporary plugging agent can be adjusted according to the width of the fracture. When the compact pressure-bearing temporary plugging agent is adjusted within the range, the performance of the whole drilling fluid cannot be changed, and the compact pressure-bearing temporary plugging agent is mixed with other components in the drilling fluid, so that the protection capability of the drilling fluid on compact sandstone matrixes and microcracks is improved.
The present invention will be described in detail below by way of examples. In the following examples of the present invention,
aiming at a low-pore ultralow-permeability compact sandstone matrix reservoir and a microfracture compact sandstone reservoir, the rheological property and the filtration property of the drilling fluid are evaluated according to the following methods: GB-T29170-2012 is adopted: and (4) testing the performance of the drilling fluid in the petroleum and natural gas industry. And testing the rheological property and the API (American Petroleum institute) filtration loss of the sample to be tested by using a six-speed viscometer and a medium-pressure filtration loss meter. Then, a sample to be tested is put into a high-temperature aging tank, is subjected to hot roll aging for 16h at the temperature of 80 ℃, and is tested for rheological property and filtration loss by the same method, and the high-temperature high-pressure filtration loss at the temperature of 80 ℃ and the pressure of 3.5 MPa.
Aiming at a low-pore ultralow-permeability compact sandstone matrix reservoir, the drilling fluid is subjected to an inhibition and anti-collapse performance test: selecting a red river oil field reservoir section shale sample, performing a drilling fluid system rolling dispersion experiment by referring to a test method of physicochemical properties of shale of oil and gas industry standard SY/T5613-2000 of the people's republic of China, and calculating the rolling recovery rate of aged rock debris. Selecting a red river oil field extension group shale core, processing the red river oil field extension group shale core into a 100-mesh specification, performing an expansion experiment by referring to a test method of physicochemical properties of shale of oil and gas industry standard SY/T5613-2000 of the people's republic of China, and testing the expansion rate.
Aiming at a low-pore ultralow-permeability compact sandstone matrix reservoir, evaluating the reservoir protection performance of the drilling fluid: selecting a low-pore ultralow-permeability compact sandstone matrix core of a red river oil field reservoir, measuring the permeability value of the core before and after the drilling fluid is polluted according to an indoor evaluation method of the oil layer damage caused by the drilling fluid completion fluid of the oil and gas industry standard SY/T T6540-2002 of the people's republic of China, and calculating the permeability recovery value. The experimental conditions are as follows: the temperature is 80 ℃, the pressure difference is 3.5MPa, and the drilling fluid pollution time is 125 min.
Aiming at a micro-fracture compact sandstone reservoir, testing the compact pressure-bearing temporary plugging performance of the drilling fluid: selecting a tight sandstone core of a reservoir in the red river oil field, carrying out seam making treatment by using a core seam making device, and controlling the opening of the microcracks by padding copper (tin) wires with different diameters. According to an evaluation method of a petroleum and gas industry standard SY/T T6540-2002 drilling fluid completion fluid damage oil reservoir indoor of the people's republic of China, permeability before and after plugging a core is tested (conditions are that the temperature is 80 ℃, the pressure difference is 3.5MPa, and the drilling fluid pollution time is 125min), and fracture plugging rate is calculated; after the blocking layer is soaked by hydrochloric acid (mass concentration is 15%), the reverse permeability is measured, and the flowback recovery rate is calculated.
The specifications and manufacturers of the raw materials involved in the following examples are as follows:
bentonite: meets the standard of GB/T20973;
tackifier: polyanionic cellulose (PAC-LV), low viscosity carboxymethyl cellulose (CMC-LV), hydroxyethyl cellulose (HEC) available from Shandong Shunyuan Petroleum science, Inc.;
high-temperature high-pressure fluid loss additives, the grades SD201 and SD202, are purchased from Stone major Innovation science and technology Limited in Dongying city, Shandong province;
lignite resin, brand SPNH, purchased from mao innovative technologies ltd, yobo, eastern, city, mountain;
potassium chloride, potassium carbonate, potassium polyacrylamide, potassium polyacrylate, purchased from Zhengzhou Oriental auxiliary agent Co., Ltd;
dodecyl dimethyl benzyl ammonium chloride, hydrolyzed polyacrylonitrile ammonium salt, purchased from Zhengzhou Oriental auxiliary agent Co., Ltd;
high acid-soluble sulfonated asphalt, brand FF-1, available from Shandong Shunyuan Petroleum science, Inc.;
lubricant: graphite 325 plus 10000 meshes, and the mark GR-1 is purchased from Stone big Innovation technology Co., Ltd, Dongying City, Shandong province;
waterproof locking agent: the designation SDFS-1, purchased from Hippocampus Dongying City Stone major Innovation science and technology Co., Ltd;
compact pressure-bearing temporary plugging agent: calcium carbonate, 40-400 mesh, brand ZDJ-1; high acid soluble fiber, brand SDCF-1, available from mao innovative technologies ltd, stone, east, west; ultra-low permeability treatment agent, brand SDN-1, purchased from great innovation technologies ltd, stone, avenue;
weighting devicePreparation: limestone with specification density of 2.5-2.7g/cm3。
The drilling fluids prepared in examples 1-7 and comparative examples 1-3 were primarily directed to low pore ultra-low permeability tight sandstone matrix reservoirs.
Example 1
According to the weight percentage, 4 weight percent of bentonite, 0.6 weight percent of tackifier (low-viscosity sodium carboxymethyl cellulose CMC-LV), 2 weight percent of high-temperature high-pressure fluid loss additive (SD201), 3 weight percent of lignite resin (SPNH), 0.3 weight percent of polyacrylamide potassium salt (KPAM), 2 weight percent of potassium chloride, 1.5 weight percent of hydrolyzed polyacrylonitrile ammonium salt (NH)4HPAN), 4 wt% high acid-soluble sulfonated asphalt (FF-1), 2 wt% lubricant (325 mesh graphite), 1 wt% waterproof locking agent (SDFS-1), 10 wt% weighting agent (limestone, 2.5g/cm3) And 69.6 wt% water to a density of 1.08g/cm3The drilling fluid of (1).
Example 2
According to the weight percentage, 3 weight percent of bentonite, 0.4 weight percent of tackifier (low-viscosity sodium carboxymethyl cellulose CMC-LV), 3 weight percent of high-temperature high-pressure fluid loss additive (SD201), 2 weight percent of lignite resin (SPNH), 0.3 weight percent of polyacrylamide potassium salt (KPAM), 1.5 weight percent of potassium chloride, and 1.5 weight percent of hydrolyzed polyacrylonitrile ammonium salt (NH)4HPAN), 2 wt% high acid-soluble sulfonated asphalt (FF-1), 3 wt% lubricant (600 mesh graphite), 0.4 wt% waterproof locking agent (SDFS-1), 20 wt% weighting agent (limestone, 2.5g/cm3) And 62.9 wt% water were mixed with stirring to give a density of 1.15g/cm3The drilling fluid of (1).
Example 3
According to the weight percentage, 2 weight percent of bentonite, 0.5 weight percent of tackifier (low-viscosity sodium carboxymethyl cellulose CMC-LV), 2 weight percent of high-temperature high-pressure fluid loss additive (SD202), 3 weight percent of lignite resin (SPNH), 0.5 weight percent of polyacrylamide potassium salt (KPAM), 1 weight percent of potassium chloride, 0.5 weight percent of hydrolyzed polyacrylonitrile ammonium salt (NH)4HPAN), 3 wt% high acid-soluble sulfonated asphalt (FF-1), 1 wt% lubricant (10000 mesh graphite), 0.8 wt% waterproof locking agent (SDFS-1), 15 wt% weighting agent (limestone, 2.5g/cm3) And 70.7 weight% water was mixed with stirring to give a mixture having a density of 1.10g/cm3The drilling fluid of (1).
Example 4
According to the weight percentage, 4 weight percent of bentonite, 0.6 weight percent of tackifier (low-viscosity sodium carboxymethyl cellulose CMC-LV), 2 weight percent of high-temperature high-pressure fluid loss additive (SD201), 3 weight percent of lignite resin (SPNH), 0.5 weight percent of polyacrylamide potassium salt (KPAM), 0.7 weight percent of potassium chloride, 0.5 weight percent of hydrolyzed polyacrylonitrile ammonium salt (NH)4HPAN), 4 wt% high acid-soluble sulfonated asphalt (FF-1), 2 wt% lubricant (325 mesh graphite), 1 wt% waterproof locking agent (SDFS-1), 15 wt% weighting agent (limestone, 2.7g/cm3) And 66.7 wt% water were mixed with stirring to give a density of 1.10g/cm3The drilling fluid of (1).
Example 5
According to the weight percentage, 4 weight percent of bentonite, 0.6 weight percent of tackifier (low-viscosity sodium carboxymethyl cellulose CMC-LV), 2 weight percent of high-temperature high-pressure fluid loss additive (SD202), 3 weight percent of lignite resin (SPNH), 0.3 weight percent of polyacrylamide potassium salt (KPAM), 2.5 weight percent of potassium chloride, 1.5 weight percent of hydrolyzed polyacrylonitrile ammonium salt (NH)4HPAN), 4 wt% high acid-soluble sulfonated asphalt (FF-1), 2 wt% lubricant (325 mesh graphite), 1 wt% waterproof locking agent (SDFS-1), 15 wt% weighting agent (limestone, 2.7g/cm3) And 64.1 wt% water were mixed with stirring to give a mixture having a density of 1.10g/cm3The drilling fluid of (1).
Example 6
According to the weight percentage, 4 weight percent of bentonite, 0.6 weight percent of tackifier (low-viscosity sodium carboxymethyl cellulose CMC-LV), 2 weight percent of high-temperature high-pressure fluid loss additive (SD201), 3 weight percent of lignite resin (SPNH), 0.3 weight percent of polyacrylamide potassium salt (KPAM), 2 weight percent of potassium chloride, 1.5 weight percent of hydrolyzed polyacrylonitrile ammonium salt (NH)4HPAN), 1 wt% high acid-soluble sulfonated asphalt (FF-1), 2 wt% lubricant (325 mesh graphite), 1 wt% waterproof locking agent (SDFS-1), 15 wt% weighting agent (limestone, 2.7g/cm3) And 67.6 wt% water were mixed with stirring to give a mixture having a density of 1.10g/cm3The drilling fluid of (1).
Example 7
According to the weight percentage, 4 weight percent of bentonite, 0.6 weight percent of tackifier (low-viscosity sodium carboxymethyl cellulose CMC-LV), 2 weight percent of high-temperature high-pressure fluid loss additive (SD201), 3 weight percent of lignite resin (SPNH), 0.3 weight percent of polyacrylamide potassium salt (KPAM), 2 weight percent of potassium chloride, 1.5 weight percent of hydrolyzed polyacrylonitrile ammonium salt (NH)4HPAN), 5 wt% high acid-soluble sulfonated asphalt (FF-1), 2 wt% lubricant (325 mesh graphite), 1 wt% waterproof locking agent (SDFS-1), 15 wt% weighting agent (limestone, 2.7g/cm3) And 63.6 wt% water were mixed with stirring to give a density of 1.10g/cm3The drilling fluid of (1).
The drilling fluids prepared in examples 8-10 and comparative examples 4-5 were primarily directed to tight sandstone microfracture reservoirs.
Example 8
According to the weight percentage, 4 weight percent of bentonite, 0.6 weight percent of tackifier (low-viscosity sodium carboxymethyl cellulose CMC-LV), 2 weight percent of high-temperature high-pressure fluid loss additive (SD201), 3 weight percent of lignite resin (SPNH), 0.3 weight percent of polyacrylamide potassium salt (KPAM), 2 weight percent of potassium chloride, 1.5 weight percent of hydrolyzed polyacrylonitrile ammonium salt (NH)4HPAN), 4 wt% of high acid-soluble sulfonated asphalt (FF-1), 2 wt% of lubricant (325 mesh graphite), 1 wt% of waterproof locking agent (SDFS-1), 4 wt% of compact pressure-bearing temporary plugging agent and 6 wt% of weighting agent (limestone, 2.5 g/cm)3) And 69.6 wt% water to a density of 1.08g/cm3The drilling fluid of (1).
Wherein, in the compact pressure-bearing temporary plugging agent, the addition amount of calcium carbonate ZDJ-1 is 65 wt%, the weight of high acid soluble fiber (SDCF-1) is 25 wt% and the weight of ultra-low permeability treatment agent (SDN-1) is 10 wt% based on the total amount of the compact pressure-bearing temporary plugging agent. The particle size distribution of calcium carbonate D50-187.9 μm, D90-365.9 μm; the length of the high acid soluble fiber is 20 μm; the particle size distribution of the ultra-low permeability treatment agent D50-66.91 μm and D90-182.2 μm.
Example 9
The procedure of example 8 was followed except that the dense pressure-bearing temporary plugging agent was added in an amount of 2% by weight and the weighting agent (limestone) was added in an amount of 8% by weight.
Wherein, in the compact pressure-bearing temporary plugging agent, the addition amount of calcium carbonate is 70 wt%, the addition amount of the high acid soluble fiber is 25 wt% and the addition amount of the ultra-low permeation treating agent is 5 wt% based on the total amount of the compact pressure-bearing temporary plugging agent.
Example 10
The procedure of example 8 was followed except that the dense pressure-bearing temporary plugging agent was added in an amount of 3% by weight and the weighting agent (limestone) was added in an amount of 7% by weight.
Wherein, in the compact pressure-bearing temporary plugging agent, the addition amount of calcium carbonate is 60 weight percent, the addition amount of the high acid soluble fiber is 30 weight percent and the addition amount of the ultra-low permeation treating agent is 10 weight percent based on the total amount of the compact pressure-bearing temporary plugging agent.
Comparative example 1
The procedure of example 1 was followed except that no hydrolyzed polyacrylonitrile ammonium salt was added and the weighting agent (limestone) was added in an amount of 11.5% by weight.
Comparative example 2
The procedure of example 1 was followed except that potassium polyacrylamide and potassium chloride were not added and the amount of the weighting agent (limestone) added was 12.3% by weight.
Comparative example 3
The procedure of example 1 was followed except that the highly acid-soluble sulfonated asphalt FF-1 was not added and the weighting agent (limestone) was added in an amount of 14% by weight.
Comparative example 4
According to the method of example 8, except that the compact pressure-bearing temporary plugging agent contains 70 wt% of calcium carbonate and 30 wt% of ultra-low permeation treatment agent, based on the total amount of the compact pressure-bearing temporary plugging agent.
Comparative example 5
According to the method of example 8, except that in the dense pressure-bearing temporary plugging agent, based on the total amount of the dense pressure-bearing temporary plugging agent, 50% by weight of calcium carbonate was added and 50% by weight of high acid-soluble fiber was added.
The drilling fluid prepared in examples 1 to 7 and comparative examples 1 to 3 for the low-pore ultra-low-permeability tight sandstone matrix reservoir is subjected to the test results of the rheological property and the fluid loss property of the drilling fluid system, and the test results of the rolling dispersivity, the swelling rate and the permeability recovery value are shown in table 1 and table 2.
TABLE 1
TABLE 1 (continuation)
In Table 1, AV represents the apparent viscosity of the drilling fluid, PV represents the plastic viscosity of the drilling fluid, YP represents the hydrodynamic shear force of the drilling fluid, Gel represents the initial and final shear of the drilling fluid, and FL representsAPIIndicates drilling fluid API fluid loss, HkExpressing the thickness of the mud cake, FLHTHPIndicating the high-temperature high-pressure filtration loss of the drilling fluid.
TABLE 2
As can be seen from the results in tables 1 and 2, the reservoir protection drilling fluid system for the low-pore ultralow-permeability compact sandstone matrix prepared in each example has the advantages of little rheological property change before and after aging, moderate viscosity and shearing force, small API fluid loss before and after aging and high-temperature and high-pressure fluid loss, capability of better preventing drilling fluid filtrate from entering the reservoir, high rolling recovery rate, low expansion rate, good system inhibition performance and high permeability recovery value after core pollution. In comparative examples 1 and 2, if only potassium salt or ammonium salt is used as the inhibitor, the rolling recovery rate of the drilling fluid is low, and the expansion rate is high; in comparative example 3, if the high acid-soluble sulfonated asphalt is not added to the raw materials, the prepared drilling fluid has high expansion rate and low permeability recovery value.
The results of the rheological and fluid loss tests on the drilling fluids for the microcracked tight sandstone reservoirs prepared in examples 8-10 and comparative examples 4-5 are shown in table 3, and the results of the tight bearing temporary plugging test are shown in table 4.
TABLE 3
In Table 3, AV represents the apparent viscosity of the drilling fluid, PV represents the plastic viscosity of the drilling fluid, YP represents the hydrodynamic shear force of the drilling fluid, Gel represents the initial and final shear of the drilling fluid, and FL representsAPIIndicates drilling fluid API fluid loss, HkExpressing the thickness of the mud cake, FLHTHPIndicating the high-temperature high-pressure filtration loss of the drilling fluid.
As can be seen from the data in Table 3, after the compact pressure-bearing temporary plugging agent is added into the raw materials, the rheological property and the filtration loss of the drilling fluid are not greatly influenced, the components are uniformly dispersed and have good compatibility, and the API filtration loss and the high-temperature and high-pressure filtration loss before and after aging are small.
TABLE 4
The results in table 4 show that, for the micro-fracture tight sandstone reservoir, the plugging rate of the tight pressure-bearing temporary plugging agent of the drilling fluid prepared in each embodiment is more than 98%, the solid phase of the drilling fluid is effectively prevented from invading the micro-fracture, the acid solubility of mud cakes is more than 70%, and the flowback recovery rate after acid washing is more than 85%. When the fracture width of the compact sandstone reservoir is increased to 287.22 mu m, the protective effect on the compact sandstone reservoir is still better.
In comparative examples 4 and 5, if the compact pressure-bearing temporary plugging agent only adopts two components or a single component, the compatibility with other components is poor, the prepared drilling fluid has poor temporary plugging rate and high leakage loss, and particularly the temporary plugging rate of the drilling fluid is worse after the crack width is widened.
The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.