Fully soluble temporary plugging steering sealing cone and temporary plugging fracturing reservoir method thereof

Abstract

The present invention discloses a fully soluble temporary plugging steering sealing cone, wherein a vulcanized rubber layer is wrapped on the surface of a double-cone metal inner core, the double-cone metal inner core and the vulcanized rubber layer are integrally formed, and the overall appearance is a jujube-shaped double-headed cone. The present invention also discloses a method for implementing temporary plugging and fracturing reservoirs based on a fully soluble temporary plugging steering sealing cone, wherein step 1 is to perform fracturing on the construction well section according to the process parameters required by the design; step 2 is to control the start and stop of the fracturing pump, and sequentially complete the operations of drilling perforating holes, placing isolation bridge plugs, and putting in temporary plugging cones; step 3 is to continuously start the fracturing pump, and perform predetermined intra-segment fracturing according to the designed process parameters, and the pump pressure can only squeeze the fracturing fluid and proppant into the un-pressed perforating holes or cracks, thereby performing steering fracturing of un-pressed formations and completing the overall fracturing in the segment. The present invention belongs to the technical field of oil well fracturing auxiliary equipment, and solves the problems in the prior art that temporary plugging agents are prone to accumulation and temporary plugging balls are prone to falling off.

Description

Technical Field

[0001] The invention belongs to the technical field of oil well fracturing auxiliary equipment, and relates to a fully soluble temporary plugging steering sealing cone. The invention also relates to a method for implementing temporary plugging and fracturing reservoirs based on the fully soluble temporary plugging steering sealing cone. Background Art

[0002] The horizontal well staged fracturing process is a commonly used oil and gas field production increase measure, especially suitable for the development of gas reservoirs and fractured oil reservoirs. The staged fracturing processes currently used in casing mainly include bridge plug perforation staged fracturing process and hydraulic jet staged fracturing process. The bridge plug perforation staged fracturing process mainly involves multiple insertions of bridge plugs to isolate the wellbore, perforation, and fracturing. This process requires multiple trips into the wellbore to complete the construction, which is discontinuous and has a long operation cycle. The other hydraulic jet staged fracturing process mainly involves inserting a sliding sleeve hydraulic jet tool in advance, opening the corresponding sliding sleeve step by step, and after completing the transformation of that stage, dropping a ball to block the channel of that stage and opening the sliding sleeve of the next stage for transformation operations, which is repeated until the staged transformation of the entire horizontal well is completed. It can be seen that the existing bridge plug is used as a segmentation tool for the exploitation of shale gas, tight gas, coalbed methane, shale oil, etc. As the well depth increases, the bridge gun string takes a long time to be lowered, the abnormality rate is high, and the operation cycle is increased; especially after the casing deformation occurs, the bridge gun string cannot be lowered, which easily causes the loss of the section.

[0003] At present, temporary plugging balls, temporary plugging agents, rope knots, etc. are often used in the market for temporary plugging of fracture mouths. The density of temporary plugging balls and temporary plugging agents is 1.2-1.5g / cm 3 , with a high specific gravity; temporary plugging agents are prone to accumulation, and have poor temporary plugging effect on the upper holes; temporary plugging balls are easy to fall off after the pressure is stopped, and stable sealing cannot be maintained, and the rope nodes are easily entangled and have insufficient strength.

[0004] Therefore, it is urgent to develop a new temporary plugging and fracturing reservoir product and application method to achieve the reliable implementation of fracture diversion and temporary plugging and fracturing reservoir. Summary of the invention

[0005] The purpose of the present invention is to provide a fully soluble temporary plugging steering sealing cone, which solves the problems in the prior art that temporary plugging agents are prone to accumulation and have poor temporary plugging effect on upper holes; and that temporary plugging balls are prone to falling off after the pressure is stopped.

[0006] Another object of the present invention is to provide a method for temporarily plugging a fracturing reservoir using a fully soluble temporary plugging steering sealing cone, which solves the problems of the prior art temporary plugging balls being easy to fall off after the pressure is stopped, failing to maintain a stable seal, and the rope nodes being easy to tangle and having insufficient strength.

[0007] The technical solution adopted by the present invention is a fully soluble temporary plugging steering sealing cone, which includes a double-cone metal core, a vulcanized rubber layer wrapped on the surface of the double-cone metal core, the double-cone metal core and the vulcanized rubber layer are integrally formed, and the overall appearance is a jujube-shaped double-headed cone.

[0008] Another technical solution adopted by the present invention is a method for implementing temporary plugging and fracturing reservoirs based on a fully soluble temporary plugging and diverting sealing cone, using the above-mentioned fully soluble temporary plugging and diverting sealing cone, referred to as a temporary plugging cone, and implementing the method according to the following steps: Step 1: According to the normal construction process, the construction well section is fractured according to the process parameters required by the design, and the fracturing pump is shut down in stages according to the design requirements; Step 2: Control the start and stop of the fracturing pump, and complete the operations of drilling and perforating blastholes, placing isolation bridge plugs, and inserting temporary plugging cones in sequence. Step 3: After temporarily plugging most of the perforations with a temporary plugging cone as a fracture diversion tool, the fracturing pump is continuously turned on to perform predetermined intra-segment fracturing according to the designed process parameters. Since the temporary plugging cone blocks the perforations or fractures that are cracked first, the pump pressure can only squeeze the fracturing fluid and proppant into the un-fractured perforations or fractures, thereby diverting the fracturing of the un-fractured formation and completing the overall fracturing in the segment.

[0009] The beneficial effects of the present invention include: 1) The temporary plugging cone is set to a jujube-shaped double-headed cone with a maximum diameter of 8mm to 35mm, making it very easy to enter the hole; the unique double-headed appearance and structure will not fall off after being inserted into the perforating hole.

[0010] 2) The temporary plugging cone is made by a special process in which a fully soluble metal core is vulcanized and covered with soluble rubber.

[0011] 3) The temporary plugging cone adopts a combination of soft and hard solutions, with a compressive strength greater than 70MPa. The material has excellent compressive strength and wear resistance; 4) After the temporary plugging cone is inserted into the hole or crack, due to the effect of the fully soluble metal core inside and the elastic rubber covering the outside, the more it is pressed, the tighter and tighter it becomes, effectively blocking the re-entry of fracturing fluid and proppant; it can plug different hole diameters (8mm~35mm) and irregular holes or cracks; 5) It can achieve 100% dissolution at a temperature of 30-150°C. After complete dissolution, there is no residue, it is non-toxic and harmless, and it is very easy to flow back. The formula design determines the dissolution time according to the temperature and liquid mineralization, and has good solubility. The soluble bridge plug is combined with a fully soluble temporary plugging cone, and the temporary plugging effect of the seam is better, making each layer more fully transformed, the reservoir utilization rate is more effective, and the recovery rate is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of the fully soluble temporary plugging steering sealing cone of the present invention; Figure 2 It is a cross-sectional view of the fully soluble temporary plugging steering sealing cone of the present invention; Figure 3 A schematic diagram of the installation position of the fully soluble temporary plugging steering sealing cone for temporarily plugging and fracturing the reservoir in the casing-changing well by the method of the present invention; Figure 4 It is a schematic diagram of the effect of using a fully soluble temporary plugging steering sealing cone to temporarily plug the fracturing hole in a casing-changing well in stages according to the method of the present invention.

[0013] In the figure, 1. vulcanized rubber layer, 2. double-cone metal core, 3. oil layer casing, 4. isolation bridge plug, 5. perforation hole, 6. temporary plugging cone. DETAILED DESCRIPTION

[0014] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0015] Reference Figure 1 , Figure 2 The structure of the fully soluble temporary plugging steering sealing cone of the present invention includes a double-conical metal core 2, a vulcanized rubber layer 1 is wrapped on the surface of the double-conical metal core 2, the double-conical metal core 2 and the vulcanized rubber layer 1 are integrally formed, and the overall shape is a jujube-shaped double-headed cone.

[0016] Both ends of the vulcanized rubber layer 1 in the length direction are set to be spherical (see Figure 2 Φa in the figure), the spherical radius of the two ends of the vulcanized rubber layer 1 is 5 to 7 mm; the outer contour of the middle part of the vulcanized rubber layer 1 is an arc-shaped transition surface (see Figure 2 Φb in the figure), the radius of the middle outer contour of the vulcanized rubber layer 1 is 7 to 35 mm; the thickness of the vulcanized rubber layer 1 is 5 to 15 mm.

[0017] The middle diameter of the biconical metal inner core 2 is 7 to 35 mm.

[0018] The sizes of the biconical metal core 2 and the vulcanized rubber layer 1 can also be customized according to user requirements.

[0019] The complete dissolution time of the fully soluble temporary plugging steering sealing cone (temporary plugging cone) shall not exceed 24 hours.

[0020] Components and preparation method of vulcanized rubber layer 1: The vulcanized rubber layer 1 is made of a fully soluble rubber synthetic material, which is synthesized at 150-180°C using a rubber mixer (using existing equipment). The formula of the fully soluble rubber is as follows: The synthesis process is: Weigh 1000g of polytetrahydrofuran ether and heat it to 120°C, add 1608g of 1,4-butanediol, 208g of silicone oil, 108g of molybdenum disulfide while stirring, and finally add 600g of MDI, stir until the MDI is completely dissolved, lower the reaction temperature to 100°C, let it stand for 2-3 minutes, and obtain a mixed material; pour the mixed material on a heating plate at 110-180°C, take it out after 100-120 minutes, and cool it to room temperature to obtain a fully soluble rubber synthetic material.

[0021] The hydroxyl value of polytetramethylene ether is 50 mgKOH / g, M^=2000.

[0022] MDI refers to diphenylmethane diisocyanate.

[0023] The double-cone metal inner core 2 is made of a fully soluble metal alloy material and can be completely dissolved in the oil layer casing.

[0024] The metal alloy material of the temporary plugging cone is processed using different formulas according to different temperature ranges.

[0025] Method 1: Temporary plugging cone suitable for well temperature range of 15-50°C (referred to as low temperature in the present invention).

[0026] The biconical metal inner core 2 is made of low-temperature soluble metal material: 85% by mass, 2-5% by zinc, 5-8% by nickel, 1-2% by cerium, and 1-2% by neodymium as basic materials (several rare metal components are used to adjust the performance of the product, the main component is magnesium-aluminum alloy), and the remainder is aluminum, totaling 100%.

[0027] The material of the outer vulcanized rubber layer 1 is a high molecular weight soluble rubber material formed by high polymerization of polyglycolic acid.

[0028] The high molecular weight polyglycolic acid is prepared from glycolic acid or methyl glycolate. The monomer glycolic acid or methyl glycolate is subjected to a pre-polycondensation reaction under the action of a catalyst to obtain a glycolic acid or methyl glycolate prepolymer with an intrinsic viscosity of 0.3 to 0.7 dl / g; and the glycolic acid or methyl glycolate prepolymer is subjected to solid phase polycondensation to obtain a polyglycolic acid elastomer with an intrinsic viscosity of more than 1.0 dl / g.

[0029] Method 2: Temporary plugging cone suitable for well temperature range of 50-80°C (referred to as medium temperature in the present invention).

[0030] The biconical metal inner core 2 is made of medium-temperature soluble metal material, and its component contents are: based on mass percentage, 90% magnesium, 1-2% nickel, 2-3% copper, 1-2% cerium, and 2-5% neodymium as basic materials (several rare metal components are used to adjust the performance of the product, and the main component is magnesium-aluminum alloy), and the remainder is aluminum, totaling 100%.

[0031] Material of the vulcanized rubber layer 1: degradable rubber based on heat-degradable polyurethane.

[0032] 0.1 mol of polyethylene adipate propylene glycol ester with a molecular weight of 1300-2500 is prepared by condensation reaction of adipic acid, ethylene glycol and 1,2-propylene glycol (1:1.26:0.14 molar ratio), added into an iron reactor whose inner wall and agitator are coated with polytetrafluoroethylene, 0.1 mol of 1,4-butanediol chain extender is added, stirring is started and the temperature is raised to the reaction temperature of 120-150°C, and 0.2 mol of MDI preheated to 80°C is quickly added, stirred rapidly for 3 minutes, poured into a preheated aluminum dish coated with silicone, and dried at 110-130°C for 3 hours to obtain an elastomer product.

[0033] Method three: Temporary plugging cone suitable for well temperature range of 80-120°C (referred to as high temperature in the present invention).

[0034] The biconical metal inner core 2 is made of high-temperature soluble metal material, and its component contents are: by mass percent, 90% magnesium, 0.5-1% nickel, 1-2% cerium, 2-3% neodymium, 1-2% manganese, 1-1.5% silicon, and 0.5-1% zirconium as basic materials (several rare metal components are used to adjust the performance of the product, and the main component is magnesium-aluminum alloy), and the remainder is aluminum, totaling 100%.

[0035] Layer 1 material of vulcanized rubber: degradable rubber with high temperature heat degradable polyurethane as the base material.

[0036] 1000g of polytetrahydrofuran ether (hydroxyl value: 50mgKOH / g, M^=2000) was heated to 120°C, 1608g of 1,4-butanediol, 208g of silicone oil, 108g of molybdenum disulfide were added, and then 600g of AMDI was added. The mixture was stirred until all the MDI was dissolved. The reaction temperature was lowered to 100°C. After standing for 2 minutes, the material was poured onto a heating plate at 110-180°C, taken out after 100 minutes, and cooled to room temperature to obtain an elastomer product.

[0037] The fully soluble temporary plugging and steering sealing cone of the present invention has a higher dissolution efficiency and a wider application range, as listed below: Low temperature series: starts to dissolve at 30-50℃; can be completely dissolved in 12-24 hours; Medium temperature series: starts to dissolve at 50-80℃; can be completely dissolved in 12-24 hours; High temperature series: starts to dissolve at 80-120℃; can be completely dissolved in 12-24 hours.

[0038] It can be seen that the different percentages of rare metals used above meet the requirements of different temperature ranges and different mineralizations. The choice of which temperature series products to use depends on the well conditions in the project area. The well parameters of each oil field block are different, including the difference in the liquid composition under the formation. The ratio of each rare metal depends on the formation temperature, liquid composition, etc. After specific analysis, the percentage of rare metals is adjusted to meet the temperature resistance / dissolution requirements.

[0039] The working pressure difference is the maximum pressure difference between the upper and lower parts of the product that the product body itself can withstand. The fully soluble temporary plugging and diverting sealing cone needs to meet a working pressure difference of 70MPa during fracturing construction, and the maximum can reach 100Mpa.

[0040] For the sake of simplicity, the fully soluble temporary plugging steering sealing cone is referred to as the temporary plugging cone 6 hereinafter.

[0041] Reference Figure 3 The working principle of the temporary plugging cone 6 of the present invention is as follows: a plurality of perforation holes 5 are opened on the wall of the oil layer casing 3 (these perforation holes 5 are formed by perforating with a perforating gun, and a perforating gun string that meets the standard requirements is lowered to a predetermined position for perforating to obtain a plurality of perforation holes 5); after the perforation holes 5 are drilled, an isolation bridge plug 4 is lowered, and the isolation bridge plug 4 is located at the downstream position of the perforation holes 5. With the isolation bridge plug 4 blocked in the oil layer casing 3, the temporary plugging cone 6 will not run to the position below the isolation bridge plug 4, and will only plug the holes above the isolation bridge plug 4; then, the temporary plugging cone 6 is placed from the surface wellhead or a special ball thrower, and the temporary plugging cone 6 is pumped to the position of the perforation hole 5, and a temporary plugging cone 6 is plugged into each selected perforation hole 5, and the process is completed.

[0042] The method for temporarily plugging a fracturing reservoir of the present invention utilizes the temporary plugging cone 6 to implement a temporary plugging fracturing reservoir operation. In the staged (layer) fracturing process, in a set section (layer) or even the whole well section fracturing process, in order to ensure that the formation is fully transformed, the temporary plugging cone 6 is used to efficiently plug the perforation holes 5 or crack holes that are cracked first, and the fracturing fluid and proppant are squeezed to the perforation holes or crack holes that have not been cracked, thereby shortening the length of the main crack and preventing the potential risk of pressure channeling with the adjacent well. During the fracturing process, the temporary plugging cone 6 is pumped to plug the perforation holes 5 or crack holes, and each section (layer) can be decomposed into multiple small levels. The perforation holes 5 or crack holes that have been filled with fluid are closed before the main crack of the section (layer) is connected to the crack network of the adjacent well, and the temporary plugging cone 6 is pumped to plug the fracturing perforations.

[0043] For example, in the perforation section under normal working conditions, a four-cluster four-shot perforation is used, and 32 perforation holes 5 are achieved after perforation, and the diameter of the perforation hole 5 is a regular size of 10 mm; the placement ratio of temporary plugging cones 6 is 80% of the number of perforation holes 5, so 32×80%=25.6 temporary plugging cones 6 need to be put in, and 26 temporary plugging cones 6 are actually put in after being rounded off. After being put in from the wellhead, the ground pump truck is at a rate of 3m3 / min displacement, pump the temporary plugging cone 6 to each perforation blasthole 5, and start the pressure after all the temporary plugging cones 6 are in place (starting the pressure means that after the temporary plugging cones are pumped to the perforation blastholes 5, most of the perforation blastholes 5 are blocked, the liquid is intercepted or the number of perforation blastholes 5 that can enter is reduced, resulting in a short period of pressure build-up).

[0044] The method for implementing temporary plugging and fracturing reservoir based on the fully soluble temporary plugging steering sealing cone of the present invention is specifically implemented according to the following steps: Step 1: According to the normal construction process, perform segment (layer) fracturing on the construction well section, perform fracturing according to the process parameters required by the design, and implement phased shutdown of the fracturing pump according to the design requirements; Step 2: Control the start and stop of the fracturing pump, and complete the operations of drilling the perforating blasthole 5, placing the isolation bridge plug 4, and inserting the temporary plugging cone 6 in sequence. After shutting down the fracturing pump, firstly, a perforating gun string is lowered into the oil layer casing 3, and multiple cluster perforations are performed at predetermined positions to obtain multiple perforation holes 5, and then the perforating gun string is removed; Then, the isolation bridge plug 4 is lowered into the oil layer casing 3 until the isolation bridge plug 4 reaches the downstream position of the perforation holes 5, and the isolation bridge plug 4 is firmly retained; Then, a temporary plugging cone 6 is put in (from the wellhead or the plug valve on one side of the fracturing pipeline). After the temporary plugging cone 6 enters the oil layer casing 3, the fracturing pump is turned on to pump the temporary plugging cone 6 to the position of the perforation hole 5. The temporary plugging cone 6 is inserted into multiple perforation holes 5 in the selected range according to the proportion of the input; The number of temporary plugging cones 6 is 0.6 to 1.2 times that of the perforating holes 5. The pumping displacement is adjusted in real time through pressure changes. The pumping displacement range is 3 to 10 m 3 / min.

[0045] Step 3: After the temporary plugging cone 6 is used as a fracture diversion tool to temporarily plug most of the perforation holes 5, the fracturing pump is continuously turned on to perform predetermined segment (layer) fracturing according to the designed process parameters. Since the temporary plugging cone 6 blocks the perforation holes 5 or fracture holes that are cracked first, the pump pressure can only squeeze the fracturing fluid and proppant into the un-fractured perforation holes 5 or fracture holes, thereby diverting the fracturing of the un-fractured formation and completing the overall fracturing in the segment (layer). Figure 4 , Figure 4 The pressure pointer of the middle pressure display gauge obviously moves to one side, which is the starting pressure display.

[0046] The method of the present invention can also be applied to casing deformation, which makes it impossible to run conventional bridge shot technology, or segment (layer) isolation tools such as soluble bridge plugs and drillable bridge plugs, as well as temporary plugging tools that require interlayer plugging.

[0047] Example 1 In Suxx horizontal well, temporary plugging cone 6 was deployed in the 11th section of fracturing construction.

[0048] The temporary plugging cone 6 in Example 1 adopts the method 1 suitable for the well temperature range of 15 to 50°C.

[0049] The biconical metal inner core 2 is made of low-temperature soluble metal materials: 85% magnesium, 5% zinc, 8% nickel, 1% cerium and 1% neodymium, with a total mass of 100%.

[0050] This embodiment uses the aforementioned sealing cone temporary plugging and fracturing reservoir method, which is specifically implemented according to the following steps: Step 1: According to the normal construction process, perform segment (layer) fracturing on the construction well section, perform fracturing according to the process parameters required by the design, and implement phased shutdown of the fracturing pump according to the design requirements; Step 2: After shutting down the fracturing pump, first use a perforating gun string to run into the oil layer casing 3, perform multi-cluster perforation at a predetermined position, and actually perforate four clusters of 32 holes in the 11th section, and then take out the perforating gun string; Then, the isolation bridge plug 4 is lowered into the oil layer casing 3 until the isolation bridge plug 4 reaches the downstream position of the perforation holes 5, and the isolation bridge plug 4 is firmly retained; Then, a temporary plugging cone 6 is put in (from the wellhead or the plug valve on one side of the fracturing pipeline). After the temporary plugging cone 6 enters the oil layer casing 3, the fracturing pump is turned on to pump the temporary plugging cone 6 to the position of the perforation hole 5. The temporary plugging cone 6 is inserted into multiple perforation holes 5 in the selected range according to the proportion of the input; Among them, the number of blastholes for 60% is 19 temporary plugging cones 6. At the same time, real-time adjustment is made through pressure changes, and the pumping displacement range is 3m 3 / min.

[0051] Step 3: After the temporary plugging cone 6 is used as a seam diversion tool to temporarily plug most of the perforation holes 5, the fracturing pump is continuously turned on to perform predetermined segment (layer) fracturing according to the designed process parameters. Since the temporary plugging cone 6 blocks the perforation holes 5 or seam holes that are cracked first, the pump pressure can only squeeze the fracturing fluid and proppant to the perforation holes 5 or seam holes that have not been cracked, thereby diverting the fracturing of the un-fractured formation and completing the overall fracturing in the segment (layer). After the temporary plugging cone 6 is in place, the pressure rises from 28Mpa to 32.5Mpa, and the temporary plugging diversion effect is very obvious.

[0052] Example 2 Well SuxxC4 is a directional well with 2 sections. Temporary plugging cone 6 was put into the second section.

[0053] The temporary plugging cone 6 in Example 2 adopts the method 1 suitable for the well temperature range of 15 to 50°C.

[0054] The biconical metal inner core 2 is made of low-temperature soluble metal materials: 85% magnesium, 4% zinc, 7% nickel, 2% cerium and 2% neodymium, with a total mass of 100%.

[0055] This embodiment uses the aforementioned sealing cone temporary plugging and fracturing reservoir method, which is specifically implemented according to the following steps: Step 1: According to the normal construction process, perform segment (layer) fracturing on the construction well section, perform fracturing according to the process parameters required by the design, and implement phased shutdown of the fracturing pump according to the design requirements; Step 2: After shutting down the fracturing pump, first use the perforating gun string to enter the oil layer casing 3, and perform multi-cluster perforation at the predetermined position, with a total of 2 clusters, 1 cluster of 3-meter guns and 48 blast holes. 1 cluster of 2-meter guns, 32 blast holes, a total of 80 blast holes. Take out the perforating gun string; Then, the isolation bridge plug 4 is lowered into the oil layer casing 3 until the isolation bridge plug 4 reaches the downstream position of the perforation holes 5, and the isolation bridge plug 4 is firmly retained; Then, a temporary plugging cone 6 is put in (from the wellhead or the plug valve on one side of the fracturing pipeline). After the temporary plugging cone 6 enters the oil layer casing 3, the fracturing pump is turned on to pump the temporary plugging cone 6 to the position of the perforation hole 5. The temporary plugging cone 6 is inserted into multiple perforation holes 5 in the selected range according to the proportion of the input; Among them, 75% of the blastholes are equipped with 60 temporary plugging cones. At the same time, real-time adjustment is made through pressure changes, and the pumping displacement range is 4m 3 / min.

[0056] Step 3: After the temporary plugging cone 6 is used as a fracture diversion tool to temporarily plug most of the perforation holes 5, the fracturing pump is continuously turned on to perform predetermined segment (layer) fracturing according to the designed process parameters. Since the temporary plugging cone 6 blocks the preferentially cracked perforation holes 5 or fracture holes, the pump pressure can only squeeze the fracturing fluid and proppant into the un-fractured perforation holes 5 or fracture holes, thereby diverting the fracturing of the un-fractured formation and completing the overall fracturing in the segment (layer).

[0057] After the temporary blocking cone 6 is in place, the pressure rises from 27 to 32Mpa, and the steering effect is very obvious.

[0058] Example 3 Mixx horizontal well has 5 sections in total. During the fracturing construction of the 5th section, a temporary plugging cone 6 was deployed.

[0059] Example 3 adopts the temporary plugging cone of method 2 which is suitable for well temperatures ranging from 50 to 80°C.

[0060] The biconical metal inner core 2 is made of medium-temperature soluble metal materials: 90% magnesium, 1% nickel, 3% copper, 1% cerium and 5% neodymium, with a total mass of 100%.

[0061] This embodiment uses the aforementioned sealing cone temporary plugging and fracturing reservoir method, which is specifically implemented according to the following steps: Step 1: According to the normal construction process, perform segment (layer) fracturing on the construction well section, perform fracturing according to the process parameters required by the design, and implement phased shutdown of the fracturing pump according to the design requirements; Step 2: After shutting down the fracturing pump, first use the perforating gun string to enter the oil layer casing 3, and perform multi-cluster perforation at the predetermined position. The gun string perforates 2 clusters, each cluster is 1 meter, and there are 32 blast holes in total. Take out the perforating gun string; Then, the isolation bridge plug 4 is lowered into the oil layer casing 3 until the isolation bridge plug 4 reaches the downstream position of the perforation holes 5, and the isolation bridge plug 4 is firmly retained; Then, a temporary plugging cone 6 is put in (from the wellhead or the plug valve on one side of the fracturing pipeline). After the temporary plugging cone 6 enters the oil layer casing 3, the fracturing pump is turned on to pump the temporary plugging cone 6 to the position of the perforation hole 5. The temporary plugging cone 6 is inserted into multiple perforation holes 5 in the selected range according to the proportion of the input; Among them, 22 temporary plugging cones are deployed at a ratio of 70%. At the same time, real-time adjustment is made through pressure changes, and the pumping displacement range is 5m 3 / min.

[0062] Step 3: After the temporary plugging cone 6 is used as a fracture diversion tool to temporarily plug most of the perforation holes 5, the fracturing pump is continuously turned on to perform predetermined segment (layer) fracturing according to the designed process parameters. Since the temporary plugging cone 6 blocks the preferentially cracked perforation holes 5 or fracture holes, the pump pressure can only squeeze the fracturing fluid and proppant into the un-fractured perforation holes 5 or fracture holes, thereby diverting the fracturing of the un-fractured formation and completing the overall fracturing in the segment (layer).

[0063] After the temporary blocking cone 6 is in place, the pressure rises from 29 to 35Mpa, and the steering effect is very obvious.

[0064] Example 4 There are 5 sections in Mixx horizontal well. In the 4th section, temporary plugging cone 6 was deployed for fracturing construction.

[0065] Example 3 adopts the temporary plugging cone of method 2 which is suitable for well temperatures ranging from 50 to 80°C.

[0066] The biconical metal inner core 2 is made of medium-temperature soluble metal materials: 90% magnesium, 2% nickel, 2% copper, 2% cerium and 4% neodymium, with a total mass of 100%.

[0067] This embodiment uses the aforementioned sealing cone temporary plugging and fracturing reservoir method, which is specifically implemented according to the following steps: Step 1: According to the normal construction process, perform segment (layer) fracturing on the construction well section, perform fracturing according to the process parameters required by the design, and implement phased shutdown of the fracturing pump according to the design requirements; Step 2: After shutting down the fracturing pump, first use the perforating gun string to enter the oil layer casing 3, and perform multi-cluster perforation at the predetermined position, perforating 2 clusters, each cluster is 1 meter, and there are 32 blast holes in total. Take out the perforating gun string; Then, the isolation bridge plug 4 is lowered into the oil layer casing 3 until the isolation bridge plug 4 reaches the downstream position of the perforation holes 5, and the isolation bridge plug 4 is firmly retained; Then, a temporary plugging cone 6 is put in (from the wellhead or the plug valve on one side of the fracturing pipeline). After the temporary plugging cone 6 enters the oil layer casing 3, the fracturing pump is turned on to pump the temporary plugging cone 6 to the position of the perforation hole 5. The temporary plugging cone 6 is inserted into multiple perforation holes 5 in the selected range according to the proportion of the input; Among them, 70% of the number of 22 temporary plugging cones 6 were deployed. At the same time, real-time adjustment was made through pressure changes, and the pumping displacement range was 3m 3 / min.

[0068] Step 3: After the temporary plugging cone 6 is used as a fracture diversion tool to temporarily plug most of the perforation holes 5, the fracturing pump is continuously turned on to perform predetermined segment (layer) fracturing according to the designed process parameters. Since the temporary plugging cone 6 blocks the preferentially cracked perforation holes 5 or fracture holes, the pump pressure can only squeeze the fracturing fluid and proppant into the un-fractured perforation holes 5 or fracture holes, thereby diverting the fracturing of the un-fractured formation and completing the overall fracturing in the segment (layer).

[0069] After the temporary blocking cone 6 is in place, the pressure rises from 23 to 29Mpa, and the steering effect is very obvious.

[0070] Example 5 There are 12 sections in Mixx horizontal well. In the 4th section fracturing construction, 6 temporary plugging cones were deployed.

[0071] Example 5 adopts the temporary plugging cone of method 3 suitable for well temperatures ranging from 80 to 120°C.

[0072] The biconical metal inner core 2 is made of high-temperature soluble metal materials: 90% magnesium, 0.8% nickel, 1.2% cerium, 2.5% neodymium, 1.5% manganese, 1.5% silicon and 0.5% zirconium, with the remainder being aluminum, totaling 100% by mass.

[0073] This embodiment uses the aforementioned sealing cone temporary plugging and fracturing reservoir method, which is specifically implemented according to the following steps: Step 1: According to the normal construction process, perform segment (layer) fracturing on the construction well section, perform fracturing according to the process parameters required by the design, and implement phased shutdown of the fracturing pump according to the design requirements; Step 2: After shutting down the fracturing pump, first use the perforating gun string to enter the oil layer casing 3, and perform multi-cluster perforation at the predetermined position. The gun string perforates 4 clusters, each cluster has 0.5 meters of gun, and a total of 32 blast holes. Take out the perforating gun string; Then, the isolation bridge plug 4 is lowered into the oil layer casing 3 until the isolation bridge plug 4 reaches the downstream position of the perforation holes 5, and the isolation bridge plug 4 is firmly retained; Then, a temporary plugging cone 6 is put in (from the wellhead or the plug valve on one side of the fracturing pipeline). After the temporary plugging cone 6 enters the oil layer casing 3, the fracturing pump is turned on to pump the temporary plugging cone 6 to the position of the perforation hole 5. The temporary plugging cone 6 is inserted into multiple perforation holes 5 in the selected range according to the proportion of the input; Among them, 23 temporary plugging cones 6 were deployed at 70% of the design requirements, and real-time adjustments were made through pressure changes. The pumping displacement range was 3m 3 / min.

[0074] Step 3: After the temporary plugging cone 6 is used as a fracture diversion tool to temporarily plug most of the perforation holes 5, the fracturing pump is continuously turned on to perform predetermined segment (layer) fracturing according to the designed process parameters. Since the temporary plugging cone 6 blocks the preferentially cracked perforation holes 5 or fracture holes, the pump pressure can only squeeze the fracturing fluid and proppant into the un-fractured perforation holes 5 or fracture holes, thereby diverting the fracturing of the un-fractured formation and completing the overall fracturing in the segment (layer).

[0075] After the temporary blocking cone 6 is in place, the pressure rises from 27 to 35.7 MPa, and the steering effect is very obvious.

[0076] Example 6 SuXXC1 well has 2 sections in total. Temporary plugging cone 6 was used in the construction of the second section.

[0077] Example 6 adopts the temporary plugging cone of method 3 suitable for well temperatures ranging from 80 to 120°C.

[0078] The biconical metal inner core 2 is made of high-temperature soluble metal materials: 90% magnesium, 0.5% nickel, 1% cerium, 2.5% neodymium, 1% manganese, 1% silicon and 0.5% zirconium, with the remainder being aluminum, with a total mass of 100%.

[0079] This embodiment uses the aforementioned sealing cone temporary plugging and fracturing reservoir method, which is specifically implemented according to the following steps: Step 1: According to the normal construction process, perform segment (layer) fracturing on the construction well section, perform fracturing according to the process parameters required by the design, and implement phased shutdown of the fracturing pump according to the design requirements; Step 2: After shutting down the fracturing pump, first use the perforating gun string to enter the oil layer casing 3, and perform multi-cluster perforation at the predetermined position. The gun string perforates 2 clusters, each cluster is 2 meters, and a total of 64 blast holes. Take out the perforating gun string; Then, the isolation bridge plug 4 is lowered into the oil layer casing 3 until the isolation bridge plug 4 reaches the downstream position of the perforation holes 5, and the isolation bridge plug 4 is firmly retained; Then, a temporary plugging cone 6 is put in (from the wellhead or the plug valve on one side of the fracturing pipeline). After the temporary plugging cone 6 enters the oil layer casing 3, the fracturing pump is turned on to pump the temporary plugging cone 6 to the position of the perforation hole 5. The temporary plugging cone 6 is inserted into multiple perforation holes 5 in the selected range according to the proportion of the input; Among them, 75% of the 48 temporary plugging cones 6 were deployed according to the design requirements, and real-time adjustments were made through pressure changes. The pumping displacement range was 3m 3 / min.

[0080] Step 3: After the temporary plugging cone 6 is used as a fracture diversion tool to temporarily plug most of the perforation holes 5, the fracturing pump is continuously turned on to perform predetermined segment (layer) fracturing according to the designed process parameters. Since the temporary plugging cone 6 blocks the preferentially cracked perforation holes 5 or fracture holes, the pump pressure can only squeeze the fracturing fluid and proppant into the un-fractured perforation holes 5 or fracture holes, thereby diverting the fracturing of the un-fractured formation and completing the overall fracturing in the segment (layer).

[0081] After the temporary blocking cone 6 is in place, the pressure rises from 24 to 33 MPa, and the steering effect is very obvious.

[0082] In short, each layer of temporary plugging cone 6 was put into use according to the design requirements, and after being pumped to the perforating blasthole 5, the pressure-generating and diverting effect was very obvious, which directly showed that the temporary plugging cone 6 successfully blocked the priority liquid-inlet blasthole in this layer, and the temporary plugging cone 6 had an obvious blocking effect on the initial main liquid-inlet channel, which enabled the cracks to be opened and extended in other blastholes that were not fully opened or difficult to open.

Claims

1. Fully soluble temporary plugging steering sealing cone, characterized by: The invention comprises a double-cone metal core (2), the surface of which is wrapped with a vulcanized rubber layer (1), the double-cone metal core (2) and the vulcanized rubber layer (1) being integrally formed, and the overall appearance is a jujube-shaped double-headed cone.

2. The fully soluble temporary plugging steering sealing cone according to claim 1 is characterized in that: The two ends of the vulcanized rubber layer (1) in the length direction are both arranged to be spherical, and the spherical radius of the two ends of the vulcanized rubber layer (1) is 5 to 7 mm; the middle outer contour of the vulcanized rubber layer (1) is an arc-shaped transition surface, and the middle outer contour radius of the vulcanized rubber layer (1) is 7 to 35 mm; the thickness of the vulcanized rubber layer (1) is 5 to 15 mm.

3. The fully soluble temporary plugging steering sealing cone according to claim 1 is characterized in that: The middle diameter of the biconical metal inner core (2) is 7 to 35 mm.

4. The fully soluble temporary plugging steering sealing cone according to claim 1 is characterized in that: The vulcanized rubber layer (1) is made of a fully soluble rubber synthetic material.

5. The fully soluble temporary plugging steering sealing cone according to claim 4 is characterized in that: The synthetic process of the rubber synthetic material is: weigh 1000g of polytetramethylene glycol and heat it to 120°C, add 1608g of 1,4-butanediol, 208g of silicone oil and 108g of molybdenum disulfide while stirring, and finally add 600g of MDI, stir until the MDI is completely dissolved, reduce the reaction temperature to 100°C, stand for 2-3min, and obtain a mixed material; pour the mixed material on a heating plate at 110-180°C, take it out after 100-120min, and cool it to room temperature to obtain a fully soluble rubber synthetic material.

6. The fully soluble temporary plugging steering sealing cone according to claim 1 is characterized in that: The biconical metal core (2) can be completely dissolved in the oil layer casing and is suitable for a well temperature range of 15 to 50°C. The biconical metal core (2) comprises, by mass, 85% magnesium, 2-5% zinc, 5-8% nickel, 1-2% cerium, 1-2% neodymium and the remainder aluminum, totaling 100%.

7. The fully soluble temporary plugging steering sealing cone according to claim 1 is characterized in that: The biconical metal core (2) can be completely dissolved in the oil layer casing and is suitable for a well temperature range of 50 to 80°C. The biconical metal core (2) comprises, by mass, 90% magnesium, 1-2% nickel, 2-3% copper, 1-2% cerium, 2-5% neodymium and the remainder aluminum, which totals 100%.

8. The fully soluble temporary plugging steering sealing cone according to claim 1, characterized in that: The biconical metal core (2) can be completely dissolved in the oil layer casing and is suitable for well temperatures ranging from 80 to 120°C. The biconical metal core (2) comprises, by mass, 90% magnesium, 0.5-1% nickel, 1-2% cerium, 2-3% neodymium, 1-2% manganese, 1-1.5% silicon, 0.5-1% zirconium and the remainder aluminum, totaling 100%.

9. A method for temporarily plugging a reservoir for fracturing based on a fully soluble temporary plugging and diverting sealing cone, using the fully soluble temporary plugging and diverting sealing cone according to any one of claims 1 to 8, hereinafter referred to as a temporary plugging cone (6), characterized in that: Follow these steps to implement: Step 1: According to the normal construction process, the construction well section is fractured according to the process parameters required by the design, and the fracturing pump is shut down in stages according to the design requirements; Step 2, controlling the start and stop of the fracturing pump, and completing the operations of drilling the perforating blasthole (5), placing the isolation bridge plug (4), and inserting the temporary plugging cone (6) in sequence; Step 3: After temporarily plugging most of the perforation holes (5) using the temporary plugging cone (6) as a fracture diversion tool, the fracturing pump is continuously turned on to perform predetermined intra-segment fracturing according to the designed process parameters. The pump pressure can only squeeze the fracturing fluid and proppant into the un-fractured perforation holes (5) or fracture holes, thereby diverting the fracturing of the un-fractured formation and completing the overall intra-segment fracturing.

10. The method for implementing temporary plugging and fracturing reservoirs based on a fully soluble temporary plugging and diverting sealing cone according to claim 9, characterized in that: In step 2, the specific process is: After shutting down the fracturing pump, firstly, a perforating gun string is lowered into the oil layer casing 3, and multiple cluster perforations are performed at predetermined positions to obtain multiple perforation holes (5), and then the perforating gun string is removed; Then, the isolation bridge plug (4) is lowered into the oil layer casing 3 until the isolation bridge plug (4) reaches the downstream position of the perforation holes (5), and the isolation bridge plug (4) is retained securely; Then, a temporary plugging cone (6) is inserted into the oil layer casing 3, and then the fracturing pump is turned on to pump the temporary plugging cone (6) to the position of the perforating blasthole (5). The temporary plugging cone (6) is inserted into a plurality of perforating blastholes (5) in the selected range according to the ratio of the temporary plugging cone (6). The number of temporary plugging cones (6) inserted is 0.6 to 1.2 times the number of perforating blastholes (5), and the pumping displacement range is 3 to 10 m 3 / min.

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