Water plugging system and high-angle crack deep source restraining and water plugging method

Abstract

The invention provides a water plugging system and a high-angle crack deep source restraining and water plugging method. The water plugging system comprises a dilution-resistant gel system, a weighted gel system, a high-temperature gel system and a high-temperature gel system. According to the high-angle crack deep source restraining and plugging method, the water plugging system serves as a water plugging agent, water plugging is conducted in a slug combination mode, and the treatment effect on a high-water-content well of a fracture-cavity type oil reservoir is remarkable.

Description

Technical Field

[0001] The invention belongs to the technical field of water plugging and recovery in fracture-cavity oil reservoirs, and in particular relates to a water plugging system and a deep source suppression and water plugging method for high-angle fractures. Background Art

[0002] The reservoirs in the fracture-cavity oil reservoir area are well developed, and oil and gas filling has been implemented. However, due to the strong bottom water capacity of the area, the production pressure difference is amplified after the pumping, the mechanical pumping is ineffective, and the water content is always high, resulting in the remaining oil being concentrated at the top. The static characterization of the reservoir shows the existence of high-angle fractures. The water drive curve shows that the deep bottom water is rapidly flooded along the high-angle fractures. The high-angle fractures in the fractures are the main water supply channels. The water plugging segment of the temperature-resistant gel + temperature-resistant gel developed in the early stage is mainly aimed at oil wells with weak bottom water energy. The range of action is in the cracks around the well, and it cannot migrate to the source of deep bottom water suppression. The plugging effect on the strong bottom water in the high-angle fractures at the bottom of the reservoir is not obvious. Although there are many research and development of agents and segment plugs for deep water plugging in the prior art, the following problems still exist:

[0003] (1) The existing technology mainly focuses on the research and development of deep water plugging agents and the evaluation of indoor test systems. There is no field application of deep water plugging agents, and the combination method of the slugs is not clear;

[0004] (2) The existing water plugging segment plug is mainly suitable for deep water plugging in sandstone, and has poor adaptability to plugging high-angle fractures and strong bottom water in carbonate fracture-cavity reservoirs;

[0005] (3) The plugging section plugs in the prior art generally have the problem of low plugging strength. The plugging range for strong bottom water is small and the plugging strength is low.

[0006] In summary, there is an urgent need to develop a deep source suppression and water plugging method for high-angle fractures in fracture-cavity reservoirs to improve the high water content of oil wells and provide support for improving the recovery of fracture-cavity reservoirs. Summary of the invention

[0007] In view of the above problems, the purpose of the present invention is to provide a deep source suppression and water plugging method for high-angle fractures in fracture-cavity oil reservoirs, so as to improve the high water content of oil wells and provide support for improving the recovery rate of fracture-cavity oil reservoirs.

[0008] To achieve the above objectives, the first aspect of the present invention provides a water plugging system, which includes a dilution-resistant jelly system, a weighted jelly system, a high-temperature jelly system and a high-temperature gel system.

[0009] According to a specific embodiment of the present invention, the dilution-resistant jelly system comprises a first anionic polyacrylamide, a first polyurethane, hydroxypropyl methylcellulose, a first phenolic crosslinking agent and a first aldehyde crosslinking agent; and / or

[0010] The weighted jelly system comprises a second anionic polyacrylamide, hydroxypropyl starch, a phenolic crosslinking agent and a weighting agent; and / or the high temperature jelly system comprises a third anionic polyacrylamide, a second polyurethane, a second phenolic crosslinking agent and a second aldehyde crosslinking agent; and / or

[0011] The high temperature gel system comprises water glass and carbon amide.

[0012] According to a specific embodiment of the present invention, the total mass of the dilution-resistant jelly system is calculated as 100%, and the dilution-resistant jelly system includes 0.6 to 1 wt% of the first anionic polyacrylamide, 0.4 to 1 wt% of the first polyurethane, 0.2 to 0.6 wt% of hydroxypropyl methylcellulose, 0.2 to 0.6 wt% of the first phenolic crosslinker, 0.2 to 0.6 wt% of the first aldehyde crosslinker and the balance of water.

[0013] According to a specific embodiment of the present invention, the mass of the weighted jelly system is calculated as 100%, and the weighted jelly system includes 0.6 to 1 wt% of the second anionic polyacrylamide, 0.6 to 1 wt% of hydroxypropyl starch, 0.2 to 0.6 wt% of phenolic crosslinking agent, 10 to 15 wt% of weighting agent and the balance of water.

[0014] According to a specific embodiment of the present invention, the mass of the high temperature gel system is calculated as 100%, and the high temperature gel system includes 0.6 to 1 wt% of the third anionic polyacrylamide, 0.4 to 1 wt% of the second polyurethane, 0.2 to 0.6 wt% of the second phenol crosslinker, 0.2 to 0.6 wt% of the second aldehyde crosslinker and the balance of water; and / or

[0015] The mass of the water glass is taken as 100%, and the amount of the carbonic acid amide is 2 to 4 wt %.

[0016] According to a specific embodiment of the present invention, the weight average molecular weight of the first anionic polyacrylamide is 12×10 4 ; and / or the weight average molecular weight of the second anionic polyacrylamide is 10×10 4 ; and / or the weight average molecular weight of the third anionic polyacrylamide is 15×10 4 ; and / or

[0017] The weight average molecular weight of the first polyurethane and the weight average molecular weight of the second polyurethane are 5500; and / or

[0018] The first phenolic cross-linking agent and the second phenolic cross-linking agent are hydroquinone; and / or

[0019] The first aldehyde cross-linking agent and the second aldehyde cross-linking agent are urotropine; and / or

[0020] The phenolic crosslinking agent is a product obtained by condensation of naphthol and formaldehyde; and / or

[0021] The weighting agent is potassium chloride.

[0022] The second aspect of the present invention provides a method for deep source suppression and water plugging of high-angle fractures, using the water plugging system described in the first aspect of the present invention as a water plugging agent, and performing water plugging in a slug combination manner;

[0023] 1) The dilution-resistant gel system is used as a pre-slug, injected into the ground, and attached to the subsequent slugs along the way to play a supporting and plugging role;

[0024] 2) Using the weighted gel system as an intermediate plug, injecting it into the ground to block deep bottom water and suppress the strength of strong bottom water;

[0025] 3) injecting the high temperature gel system as a post-segment plug to plug near the wellbore and expand the plugging range;

[0026] 4) Injecting the high temperature gel system as a sealing segment plug to prevent the front segment plug, the middle segment plug and the rear segment plug from spitting back and blocking the wellbore.

[0027] In the present invention, high-angle fractures refer to formation fractures whose angle with the well axis is between 45° and 70°.

[0028] In the present invention, bottom water refers to the water that fills the bottom of oil and gas and supports oil and gas during oil field production; strong bottom water refers to bottom water with strong energy and a water body multiple greater than 30.

[0029] According to a specific embodiment of the present invention, the method further comprises step 5), injecting water as a displacement plug.

[0030] According to a specific embodiment of the present invention, the total injection volume of the leading slug, the middle slug, the trailing slug, the sealing slug and the displacement slug is calculated as 100%, the injection volume of the leading slug accounts for 4 to 8%, the injection volume of the middle slug accounts for 25 to 30%, the injection volume of the trailing slug accounts for 30 to 36%, the injection volume of the sealing slug accounts for 10 to 16% and the injection volume of the displacement slug accounts for 10 to 31%.

[0031] In the bottom water shielding method provided by the present invention, the injection speed of each slug and the total injection volume of the front slug, the middle slug, the rear slug and the sealing slug can also be determined according to the actual situation of on-site construction.

[0032] The water plugging system according to the first aspect of the present invention or the high-angle fracture deep source suppression water plugging method according to the second aspect of the present invention is used in water plugging of fracture-cavity oil reservoirs.

[0033] Beneficial effects of the present invention:

[0034] In view of the problem that deep water plugging agents and water plugging segments in the prior art have poor plugging effects on high-angle fractures in fracture-cavity oil reservoirs, the present invention provides a water plugging system and a deep source suppression water plugging method for high-angle fractures. The water plugging system includes a dilution-resistant gel system, a weighted gel system, a high-temperature gel system and a high-temperature gel system. The deep source suppression plugging method for high-angle fractures uses the water plugging system as a water plugging agent and performs water plugging in the form of segment-plug combination. Specifically, the dilution-resistant gel system is used as a front segment plug to support and plug subsequent segment plugs, the weighted gel system is used as an intermediate segment plug to plug deep bottom water and suppress bottom water strength, the high-temperature gel system is used as a rear segment plug to plug near the well to expand the plugging range, and the high-temperature gel system is used as a sealing segment plug to prevent the front segment plug, the intermediate segment plug and the rear segment plug from spitting back and blocking the wellbore, and finally water is preferably injected as a displacement segment plug. Among them, the middle segment plug and the rear segment plug cooperate to block the bottom water from far to near, inhibit the bottom water from rising, so as to facilitate the exploitation of the remaining crude oil. The water blocking system and the deep source suppression water blocking method of high-angle fractures provided by the present invention have been actually applied in high-water-content wells with a water content of 70% to 98% in fracture-cavity reservoirs. After treatment, the production of TPX1 well, TPX2 well, and TPX3 well are as follows: the daily oil production increases from 3.1t, 0.8t, and 0t before treatment to 13.5t, 8.5t, and 11.1t after treatment; continuous production for 190 days, 180 days, and 200 days; the cumulative oil production increases are 1419.3t, 1489.6t, and 583.6t, respectively, and they are still increasing oil production, and the treatment effect is significant. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The results show that the water plugging system and the deep source suppression water plugging method for high-angle fractures provided by the present invention were used to treat the TPX1 well in Example 1;

[0036] Figure 2 The results show that Example 2 uses the water plugging system and the high-angle fracture deep source suppression water plugging method provided by the present invention to treat the TPX2 well;

[0037] Figure 3 The results show that Example 3 uses the water plugging system and high-angle fracture deep source suppression and water plugging method provided by the present invention to treat the TPX3 well. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with examples, but the examples of the present invention are only exemplary descriptions, and the implementation methods do not constitute limitations of the present invention under any circumstances.

[0039] A first aspect of the present invention provides a water plugging system, which includes a dilution-resistant jelly system, a weighted jelly system, a high-temperature jelly system and a high-temperature gel system.

[0040] According to a specific embodiment of the present invention, the dilution-resistant jelly system comprises a first anionic polyacrylamide, a first polyurethane, hydroxypropyl methylcellulose, a first phenolic crosslinking agent and a first aldehyde crosslinking agent; and / or

[0041] The weighted jelly system comprises a second anionic polyacrylamide, hydroxypropyl starch, a phenolic crosslinking agent and a weighting agent; and / or the high temperature jelly system comprises a third anionic polyacrylamide, a second polyurethane, a second phenolic crosslinking agent and a second aldehyde crosslinking agent; and / or

[0042] The high temperature gel system comprises water glass and carbon amide;

[0043] Preferably, the mass of the water glass is taken as 100%, wherein the content of sodium silicate is 70wt%;

[0044] Preferably, the water glass is diluted with water in a volume ratio of 1:(1 to 2) (eg, a volume ratio of water glass: water is 1:1, 1:1.5, 1:2).

[0045] According to a specific embodiment of the present invention, the total mass of the dilution-resistant jelly system is calculated as 100%, and the dilution-resistant jelly system includes 0.6 to 1 wt% of the first anionic polyacrylamide, 0.4 to 1 wt% of the first polyurethane, 0.2 to 0.6 wt% of hydroxypropyl methylcellulose, 0.2 to 0.6 wt% of the first phenolic crosslinker, 0.2 to 0.6 wt% of the first aldehyde crosslinker and the balance of water.

[0046] According to a specific embodiment of the present invention, the mass of the weighted jelly system is calculated as 100%, and the weighted jelly system includes 0.6 to 1 wt% of the second anionic polyacrylamide, 0.6 to 1 wt% of hydroxypropyl starch, 0.2 to 0.6 wt% of phenolic crosslinking agent, 10 to 15 wt% of weighting agent and the balance of water.

[0047] According to a specific embodiment of the present invention, the mass of the high temperature gel system is calculated as 100%, and the high temperature gel system includes 0.6 to 1 wt% of the third anionic polyacrylamide, 0.4 to 1 wt% of the second polyurethane, 0.2 to 0.6 wt% of the second phenol crosslinker, 0.2 to 0.6 wt% of the second aldehyde crosslinker and the balance of water; and / or

[0048] The mass of the water glass is taken as 100%, and the amount of the carbonic acid amide is 2 to 4 wt %.

[0049] According to a specific embodiment of the present invention, the total mass of the dilution-resistant gel system is calculated as 100%, and the dilution-resistant gel system includes 0.6wt% of the first anionic polyacrylamide, 0.4wt% of the first polyurethane, 0.2wt% of hydroxypropyl methylcellulose, 0.2wt% of the first phenolic crosslinking agent, 0.2wt% of the first aldehyde crosslinking agent and the balance of water; and / or

[0050] The weight of the weighted jelly system is calculated as 100%, and the weighted jelly system includes 0.6 wt % of the second anionic polyacrylamide, 0.6 wt % of hydroxypropyl starch, 0.2 wt % of phenolic crosslinking agent, 10 wt % of weighting agent and the balance of water;

[0051] and / or the mass of the high temperature gel system is taken as 100%, and the high temperature gel system comprises 0.6wt% of the third anionic polyacrylamide, 0.4wt% of the second polyurethane, 0.2wt% of the second phenolic crosslinking agent, 0.2wt% of the second aldehyde crosslinking agent and the balance water; and / or

[0052] The mass of the water glass is calculated as 100%, and the amount of the carbonamide used is 2 wt %.

[0053] According to a specific embodiment of the present invention, the total mass of the dilution-resistant gel system is calculated as 100%, and the dilution-resistant gel system includes 0.8wt% of the first anionic polyacrylamide, 0.6wt% of the first polyurethane, 0.4wt% of hydroxypropyl methylcellulose, 0.4wt% of the first phenolic crosslinking agent, 0.4wt% of the first aldehyde crosslinking agent and the balance of water; and / or

[0054] The weight of the weighted jelly system is calculated as 100%, and the weighted jelly system includes 0.8 wt % of the second anionic polyacrylamide, 0.8 wt % of hydroxypropyl starch, 0.4 wt % of a phenolic crosslinking agent, 12 wt % of a weighting agent, and the balance of water;

[0055] and / or the mass of the high temperature gel system is taken as 100%, and the high temperature gel system comprises 0.8wt% of the third anionic polyacrylamide, 0.6wt% of the second polyurethane, 0.4wt% of the second phenolic crosslinking agent, 0.4wt% of the second aldehyde crosslinking agent and the balance water; and / or

[0056] The mass of the water glass is calculated as 100%, and the amount of the carbonic acid amide is 3wt%.

[0057] According to a specific embodiment of the present invention, the total mass of the dilution-resistant gel system is calculated as 100%, and the dilution-resistant gel system includes 1wt% of the first anionic polyacrylamide, 1wt% of the first polyurethane, 0.6wt% of hydroxypropyl methylcellulose, 0.6wt% of the first phenolic crosslinking agent, 0.6wt% of the first aldehyde crosslinking agent and the balance of water; and / or

[0058] The weight of the weighted jelly system is calculated as 100%, and the weighted jelly system comprises 1wt% of the second anionic polyacrylamide, 1wt% of hydroxypropyl starch, 0.6wt% of phenolic crosslinking agent, 15wt% of weighting agent and the balance of water; and / or

[0059] The mass of the high temperature gel system is calculated as 100%, and the high temperature gel system includes 1wt% of the third anionic polyacrylamide, 1wt% of the second polyurethane, 0.6wt% of the second phenol crosslinking agent, 0.6wt% of the second aldehyde crosslinking agent and the balance water; and / or

[0060] The mass of the water glass is calculated as 100%, and the amount of the carbonamide used is 4wt%.

[0061] According to a specific embodiment of the present invention, the dilution-resistant gel system has a temperature resistance of not less than 130°C and / or a salt resistance of not less than 20×10 4 mg / L; and / or the gelling time at 130℃ is less than 2h; and / or the gelling strength is not less than Grade H; and / or

[0062] The weighted gel system has a temperature resistance of not less than 130°C and / or a salt resistance of not less than 20×10 4 mg / L; and / or density of 1.16 to 1.2 g / cm 3 ; and / or 130°C gelling time is 1 to 2 hours and / or gelling strength is H to I level; and / or

[0063] The high temperature gel system has a temperature resistance of not less than 130°C and / or a salt resistance of not less than 20×10 4 mg / L; and / or the gelling time at 130℃ is 1 to 3h; and / or the gelling strength is not less than Grade H; and / or

[0064] The high temperature gel system has a gelling time of 1 to 3 hours at 130° C. and / or a gelling strength of not less than Grade I.

[0065] In the present invention, gel strength level H and level I are gel strength levels measured by the Sydansk visual code method. Gel strength level H refers to a slightly deformable non-flowing gel, and only the gel surface deforms when flipped; gel strength level I refers to a rigid gel, and the gel surface does not deform when flipped.

[0066] According to a specific embodiment of the present invention, the weight average molecular weight of the first anionic polyacrylamide is 12×10 4 ; and / or the weight average molecular weight of the second anionic polyacrylamide is 10×10 4 ; and / or the weight average molecular weight of the third anionic polyacrylamide is 15×10 4 ; and / or

[0067] The weight average molecular weight of the first polyurethane and the weight average molecular weight of the second polyurethane are 5500; and / or

[0068] The first phenolic cross-linking agent and the second phenolic cross-linking agent are hydroquinone; and / or

[0069] The first aldehyde cross-linking agent and the second aldehyde cross-linking agent are urotropine; and / or

[0070] The phenolic crosslinking agent is a product obtained by condensation of naphthol and formaldehyde; and / or

[0071] The weighting agent is potassium chloride.

[0072] Preferably, the CAS number of the hydroxypropyl methylcellulose is 9004-65-3; and / or

[0073] The CAS number of the hydroxypropyl starch is 68584-86-1.

[0074] The second aspect of the present invention provides a method for deep source suppression and water plugging of high-angle fractures, using the water plugging system described in the first aspect of the present invention as a water plugging agent, and performing water plugging in a slug combination manner;

[0075] 1) The dilution-resistant gel system is used as a pre-slug, injected into the ground, and attached to the subsequent slugs along the way to play a supporting and plugging role;

[0076] 2) Using the weighted gel system as an intermediate plug, injecting it into the ground to block deep bottom water and suppress the strength of strong bottom water;

[0077] 3) injecting the high temperature gel system as a post-segment plug to plug near the wellbore and expand the plugging range;

[0078] 4) Injecting the high temperature gel system as a sealing segment plug to prevent the front segment plug, the middle segment plug and the rear segment plug from spitting back and blocking the wellbore.

[0079] According to a specific embodiment of the present invention, the method further comprises step 5), injecting water as a displacement plug.

[0080] According to a specific embodiment of the present invention, the total injection volume of the leading slug, the middle slug, the trailing slug, the sealing slug and the displacement slug is calculated as 100%, the injection volume of the leading slug accounts for 4 to 8%, the injection volume of the middle slug accounts for 25 to 30%, the injection volume of the trailing slug accounts for 30 to 36%, the injection volume of the sealing slug accounts for 10 to 16% and the injection volume of the displacement slug accounts for 10 to 31%.

[0081] According to a specific embodiment of the present invention, the injection speeds of the front slug, the middle slug, the rear slug, the sealing slug and the displacement slug are independently 18 to 30 m / s. 3 / h;

[0082] Preferably, the injection speed of the front slug, the middle slug, the rear slug, the sealing slug and the displacement slug is 24m / s. 3 / h.

[0083] According to a specific embodiment of the present invention, the total injection volume of the front slug, the middle slug, the rear slug and the sealing slug is not more than 300m 3 .

[0084] The water plugging system according to the first aspect of the present invention or the high-angle fracture deep source suppression water plugging method according to the second aspect of the present invention is used in water plugging of fracture-cavity oil reservoirs.

[0085] The method for deep source suppression and water plugging in high-angle fractures provided by the present invention firstly injects the dilution-resistant gel system into the ground as a front segment plug based on the characteristics of large volume and strong hydrophilicity of the water channel. After the dilution-resistant gel is injected into the ground, it slowly condenses on the passage through which it flows under the action of formation pressure and temperature, playing a role in supporting and plugging subsequent segment plugs; then the weighted gel system is injected into the ground as an intermediate segment plug, and for the high-angle fracture system around the well, it can enter the deep part of the high-angle fracture to plug the source of strong bottom water to slow down the rise of bottom water, laying a foundation for the plugging of subsequent segment plugs; then the high-temperature gel system is injected as a rear segment On the basis of the support and plugging of the front slug + the middle slug + the suppression of the deep bottom water source, the high-temperature gel plugs the more developed fracture system around the well, and cooperates with the weighted gel of the middle slug to further block the bottom water from far to near, suppress the bottom water strength, and delay the rise of the bottom water, so as to facilitate the exploitation of the remaining oil in the upper part of the well; then the high-temperature gel system is injected as a sealing slug to prevent the injected front slug, middle slug and rear slug from spitting back and blocking the wellbore under the action of formation water; finally, water is preferably injected as a displacement slug, and the displacement slug is squeezed into the formation, which further enhances the water blocking effect of the aforementioned slug, and also can avoid blockage in the wellbore.

[0086] Water plugging system

[0087] The raw material information used in Examples 1 to 3 is as follows:

[0088] The first anionic polyacrylamide: anionic polyacrylamide produced by Xinjiang Botianyuan Environmental Protection Materials Co., Ltd., with a molecular weight of 12×10 4 ;

[0089] Second anionic polyacrylamide: anionic polyacrylamide produced by Henan Hancheng Environmental Protection Company, with a molecular weight of 10×10 4 ;

[0090] The third anionic polyacrylamide: anionic polyacrylamide produced by Henan Duohui Chemical Products Co., Ltd., with a molecular weight of 15×10 4 ;

[0091] The first polyurethane and the second polyurethane are polyurethanes produced by Guangzhou Haoyi New Materials Technology Co., Ltd., Guangdong Province, with a molecular weight of 5500;

[0092] Hydroxypropyl methylcellulose: Hydroxypropyl methylcellulose produced by Shandong Qingyixin Chemical Technology Co., Ltd., CAS number is 9004-65-3;

[0093] Hydroxypropyl starch: Hydroxypropyl starch produced by Nanjing Songguan Biotechnology Co., Ltd., CAS No. 68584-86-1;

[0094] The first phenolic cross-linking agent and the second phenolic cross-linking agent: hydroquinone;

[0095] The first aldehyde cross-linking agent, the second aldehyde cross-linking agent: hexamethylenetetramine;

[0096] Phenolic crosslinker: a product obtained by condensation of naphthol and formaldehyde, purchased from Jiangsu Yaohe Chemical Technology Co., Ltd.;

[0097] Weighting agent: Potassium chloride produced by Shaanxi Chenming Biotechnology Co., Ltd., CAS No. 7447-40-7;

[0098] Water glass: sodium silicate content is about 70wt%, produced by Hunan Yueyang Tianying Chemical Co., Ltd.;

[0099] Carbonamide: Produced by Xinjiang Tianye Co., Ltd.

[0100] Example 1

[0101] The water plugging system provided in this embodiment is as follows:

[0102] (1) Dilution-resistant gel system: The total mass of the dilution-resistant gel system is 100%, and the dilution-resistant gel system includes 0.6 wt% of a first anionic polyacrylamide, 0.4 wt% of a first polyurethane, 0.2 wt% of hydroxypropyl methylcellulose, 0.2 wt% of a first phenolic crosslinking agent hydroquinone, 0.2 wt% of a first aldehyde crosslinking agent urotropine, and the balance of water; the above components are weighed according to proportion, mixed, and stirred to obtain a dilution-resistant gel system;

[0103] (2) a weighted gel system: the total mass of the weighted gel system is taken as 100%, and the weighted gel system comprises 0.6 wt% of a second anionic polyacrylamide, 0.6 wt% of hydroxypropyl starch, 0.2 wt% of a phenolic crosslinking agent, 10 wt% of a weighting agent potassium chloride, and the balance of water; the above components are weighed in proportion, mixed, and stirred to obtain a weighted gel system;

[0104] (3) High temperature gel system: The total mass of the high temperature gel system is 100%, and the high temperature gel system includes 0.6 wt% of the third anionic polyacrylamide, 0.4 wt% of the second polyurethane, 0.2 wt% of the second phenolic crosslinking agent hydroquinone, 0.2 wt% of the second aldehyde crosslinking agent urotropine, and the balance of water; the above components are weighed according to proportion, mixed, and stirred to obtain a high temperature gel system;

[0105] (4) High temperature gel system: dilute water glass with clean water (the volume ratio of water glass: water is 1:1), add carbonamide, and the amount of carbonamide is 2wt% of the mass of water glass; weigh the above components according to proportion, mix them, and stir them evenly to obtain a high temperature gel system.

[0106] Example 2

[0107] The water plugging system provided in this embodiment is as follows:

[0108] (1) Dilution-resistant gel system: The total mass of the dilution-resistant gel system is 100%, and the dilution-resistant gel system includes 0.8 wt% of a first anionic polyacrylamide, 0.6 wt% of a first polyurethane, 0.4 wt% of hydroxypropyl methylcellulose, 0.4 wt% of a first phenolic crosslinking agent hydroquinone, 0.4 wt% of a first aldehyde crosslinking agent urotropine, and the balance of water; the above components are weighed in proportion, mixed, and stirred to obtain a dilution-resistant gel plug;

[0109] (2) Weighted gel system: The total mass of the weighted gel system is 100%, and the weighted gel system includes 0.8 wt% of a second anionic polyacrylamide, 0.8 wt% of hydroxypropyl starch, 0.4 wt% of a phenolic crosslinking agent, 12 wt% of a weighting agent potassium chloride, and the balance of water; the above components are weighed in proportion, mixed, and stirred to obtain a weighted gel system;

[0110] (3) High temperature gel system: The total mass of the high temperature gel system is 100%, and the high temperature gel system includes 0.8 wt% of the third anionic polyacrylamide, 0.6 wt% of the second polyurethane, 0.4 wt% of the second phenolic crosslinking agent hydroquinone, 0.4 wt% of the second aldehyde crosslinking agent urotropine, and the balance of water; the above components are weighed according to proportion, mixed, and stirred to obtain a high temperature gel system;

[0111] (4) High temperature gel system: dilute water glass with clean water (the volume ratio of water glass: water is 1:1.5), add carbonamide, and the amount of carbonamide is 3wt% of the mass of water glass; weigh the above components according to proportion, mix them, and stir them evenly to obtain a high temperature gel system.

[0112] Example 3

[0113] The water plugging system provided in this embodiment is as follows:

[0114] (1) Dilution-resistant gel system: The total mass of the dilution-resistant gel system is 100%, and the dilution-resistant gel system includes 1.0 wt% of a first anionic polyacrylamide, 1.0% of a first polyurethane, 0.6 wt% of hydroxypropyl methylcellulose, 0.6 wt% of a first phenolic crosslinking agent hydroquinone, 0.6 wt% of a first aldehyde crosslinking agent urotropine, and the balance of water; the above components are weighed in proportion, mixed, and stirred to obtain a dilution-resistant gel plug;

[0115] (2) a weighted gel system: the total mass of the weighted gel system is taken as 100%, and the weighted gel system comprises 1.0 wt% of a second anionic polyacrylamide, 1.0 wt% of hydroxypropyl starch, 0.6 wt% of a phenolic crosslinking agent, 15 wt% of a weighting agent potassium chloride, and the balance of water; the above components are weighed in proportion, mixed, and stirred to obtain a weighted gel system;

[0116] (3) High temperature gel system: The total mass of the high temperature gel system is 100%, and the high temperature gel system includes 1.0 wt% of the third anionic polyacrylamide, 1.0 wt% of the second polyurethane, 0.6 wt% of the second phenol crosslinking agent hydroquinone, 0.6 wt% of the second aldehyde crosslinking agent urotropine, and the balance of water; the above components are weighed according to proportion, mixed, and stirred to obtain a high temperature gel system;

[0117] (4) High temperature gel system: dilute water glass with clean water (the volume ratio of water glass: water is 1:2), add carbonamide, and the amount of carbonamide is 4wt% of the mass of water glass; weigh the above components according to proportion, mix them, and stir them evenly to obtain a high temperature gel system.

[0118] Test Example 1-Water Plugging System Performance Evaluation

[0119] At room temperature, the mineralization degree was 20×104 The raw materials were weighed according to the dosage ratio of each component recorded in Examples 1 to 3 with a concentration of mg / L of simulated formation water, and each raw material was completely dissolved in the simulated formation water to obtain dilution-resistant gel-1, weighted gel-1, high-temperature gel-1, high-temperature gel-1, dilution-resistant gel-2, weighted gel-2, high-temperature gel-2, high-temperature gel-2, dilution-resistant gel-3, weighted gel-3, high-temperature gel-3, and high-temperature gel-3 for testing in turn;

[0120] A. Determination of gelling time and gelling strength: 30 g of each of the dilution-resistant gel, weighted gel, high-temperature gel and high-temperature gel prepared in this test example were weighed and placed in a thermostat set at 130° C. for aging. During the aging process, the gelling conditions of each gel and gel were observed. The gelling time and gelling strength of each gel and gel were measured according to the Sydansk visual code method. The results are shown in Table 1.

[0121] B. Density measurement: The density of the dilution-resistant jelly, weighted jelly, high-temperature jelly and high-temperature gel prepared in this test example was measured using a digital liquid density meter. The results are shown in Table 1.

[0122] C. High temperature stability determination: Weigh 30 g of each of the dilution-resistant jelly, weighted jelly, high temperature jelly and high temperature gel prepared in this test example and place them in containers, seal them, and then start aging in a constant temperature box set at 130°C; after gelation, continue aging at 130°C and observe the dehydration after gelation, observe the dehydration amount by visual inspection, and divide the dehydration amount by the volume after gelation to obtain the dehydration rate; here, the aging days when the dehydration rate reaches 10% are used as the duration of high temperature stability, and the results are shown in Table 1.

[0123] Table 1. Performance determination of water plugging system

[0124]

[0125] It can be seen from the measurement results in Table 1 that the water plugging system provided by the present invention has a suitable gelling time, sufficient gelling strength and suitable density at 130°C, has good high-temperature stability, and is suitable for plugging high-angle fractures in fracture-cavity reservoirs.

[0126] Implementing the method of deep source suppression and water blocking in high-angle fractures

[0127] During the development of fracture-cavity oil reservoirs, 152 out of 296 wells had high water content of 70% to 98%, accounting for 51.35% of the wells with high water content. The water plugging system and the deep source suppression and water plugging method of high-angle fractures provided by the present invention were used to treat the high-water-content wells. The angles between the formation fractures of TPX1 well, TPX2 well, and TPX3 well and the well axis are 50°, 60°, and 65°, respectively, which are high-angle fractures. The following is a detailed description of TPX1 well, TPX2 well, and TPX3 well as examples.

[0128] Example 4

[0129] The water plugging system provided in Example 1 was used to implement the high-angle fracture deep source suppression water plugging method provided by the present invention on the TPX1 well, and the construction was carried out by the fixed pipe string reverse injection method. Specifically:

[0130] 1) The dilution-resistant gel system provided in Example 1 is used as a pre-slug, injected into the ground, and attached to the subsequent slugs along the way to play a supporting and plugging role;

[0131] 2) Using the weighted gel system provided in Example 1 as an intermediate plug, injecting it into the ground to block deep bottom water and suppress the strength of strong bottom water;

[0132] 3) injecting the high temperature gel system provided in Example 1 as a post-slug to plug the wellbore near the wellbore and expand the plugging range;

[0133] 4) injecting the high temperature gel system provided in Example 1 as a sealing slug to prevent the front slug, the middle slug and the rear slug from spitting back and blocking the wellbore;

[0134] 5) Injecting oilfield water as a displacement plug to further enhance the water blocking effect of the plug and avoid blockage in the wellbore. After the well is soaked, it can be sprayed for production;

[0135] During the construction process, the injection speed of each segment plug was 18m 3 / h, the cumulative injection volume of each segment plug and oilfield water is 300m 3 , of which: the injection volume of the front slug accounts for 4%, and the cumulative injection volume is 12m 3 The injection volume of the middle section plug accounts for 25%, and the cumulative injection volume is 75m 3 The injection volume of the rear slug accounts for 30%, and the cumulative injection volume is 90m 3 The injection volume of the sealing segment plug accounts for 10%, and the cumulative injection volume is 30m 3 The cumulative injection volume of oilfield water is 93m 3 .

[0136] Figure 1The treatment of the TPX1 well in this embodiment is shown. It can be seen that after treatment, the daily liquid production of the TPX1 well is 34.8 tons, the daily oil production increases from 3.1 tons before treatment to 13.5 tons after treatment, and the water content is 61.3%. At present, the well has been in continuous production for 190 days, with a cumulative increase of 1419.3 tons of oil, and is still increasing oil.

[0137] Example 5

[0138] Using the water plugging system provided in Example 2, the high-angle fracture deep source suppression water plugging method provided by the present invention was implemented on the TPX2 well, and the construction was carried out by the fixed pipe string reverse injection method. Specifically:

[0139] 1) The dilution-resistant jelly system provided in Example 2 is used as a pre-slug, injected into the ground, and attached to the subsequent slugs along the way to play a supporting and plugging role;

[0140] 2) Using the weighted gel system provided in Example 2 as an intermediate plug, injecting it into the ground to block deep bottom water and suppress the strength of strong bottom water;

[0141] 3) injecting the high-temperature gel system provided in Example 2 as a post-slug to plug the wellbore near the wellbore and expand the plugging range;

[0142] 4) injecting the high temperature gel system provided in Example 2 as a sealing slug to prevent the front slug, the middle slug and the rear slug from spitting out and blocking the wellbore;

[0143] 5) Injecting oilfield water as a displacement plug to further enhance the water blocking effect of the plug and avoid blockage in the wellbore. After the well is soaked, it can be sprayed for production;

[0144] During the construction process, the injection speed of each segment plug was 24m 3 / h, each segment plug and oilfield water are injected 400m 3 , of which: the injection volume of the front slug accounts for 6%, and the cumulative injection volume is 24m 3 The injection volume of the main slug accounts for 28%, and the cumulative injection volume is 112m 3 ; The injection volume of the rear slug accounts for 34%, and the cumulative injection volume is 136m 3 ; The injection volume of the sealing segment plug accounts for 14%, and the cumulative injection volume is 56m 3 ; The cumulative injection volume of oilfield water is 72m 3 .

[0145] Figure 2The treatment of the TPX2 well in this embodiment is shown. It can be seen that after treatment, the TPX2 well produces 16.8 tons of liquid per day, and the daily oil production increases from 0.8 tons before treatment to 8.5 tons after treatment, with a water content of 49.6%. At present, the well has been in continuous production for 180 days, with a cumulative increase of 1489.6 tons of oil, and is still increasing oil.

[0146] Example 6

[0147] Using the water plugging system provided in Example 3, the high-angle fracture deep source suppression water plugging method provided by the present invention was implemented on the TPX3 well, and the construction was carried out by the fixed pipe string reverse injection method. Specifically:

[0148] 1) The dilution-resistant jelly system provided in Example 3 is used as a pre-slug, injected into the ground, and attached to the subsequent slugs along the way to play a supporting and plugging role;

[0149] 2) Using the weighted gel system provided in Example 3 as an intermediate plug, injecting it into the ground to block deep bottom water and suppress the strength of strong bottom water;

[0150] 3) injecting the high-temperature gel system provided in Example 3 as a post-slug to plug the wellbore near the wellbore and expand the plugging range;

[0151] 4) injecting the high temperature gel system provided in Example 3 as a sealing slug to prevent the front slug, the middle slug and the rear slug from spitting back and blocking the wellbore;

[0152] 5) Injecting oilfield water as a displacement plug to further enhance the water blocking effect of the plug, and also avoid blockage in the wellbore. After the well is soaked, it can be sprayed for production;

[0153] During the construction process, the injection speed of each segment plug is 30m 3 / h, each segment plug and oilfield water are injected 500m 3 , of which: the injection volume of the front slug accounts for 8%, and the cumulative injection volume is 40m 3 ; The injection volume of the main slug accounts for 30%, and the cumulative injection volume is 150m 3 ; The injection volume of the rear slug accounts for 36%, and the cumulative injection volume is 180m 3 ; The injection volume of the sealing segment plug accounts for 16%, and the cumulative injection volume is 80m 3 ; Oilfield water; Cumulative injection volume is 50m 3 .

[0154] Figure 3The treatment of the TPX3 well in this embodiment is shown. It can be seen that after treatment, the TPX3 well produces 11.8 tons of liquid per day, and the daily oil production increases from 0 tons before treatment to 11.1 tons after treatment, with a water content of 6.1%. At present, the well has been in continuous production for 200 days, with a cumulative increase of 583.6 tons of oil, and is still increasing oil.

[0155] Although the present invention has been described with reference to specific embodiments, it will be appreciated by those skilled in the art that various changes may be made without departing from the true spirit and scope of the present invention. In addition, the subject matter, spirit and scope of the present invention may be varied to accommodate specific situations, materials, material combinations and methods. All of these changes are included within the scope of the claims of the present invention.

Claims

1. A water plugging system, comprising a dilution-resistant gel system, a weighted gel system, a high-temperature gel system and a high-temperature gel system.

2. The water blocking system according to claim 1, It is characterized in that The dilution-resistant gel system comprises a first anionic polyacrylamide, a first polyurethane, hydroxypropyl methylcellulose, a first phenolic crosslinking agent and a first aldehyde crosslinking agent; and / or the weighted jelly system comprises a second anionic polyacrylamide, hydroxypropyl starch, a phenolic crosslinking agent and a weighting agent; and / or The high temperature gel system comprises a third anionic polyacrylamide, a second polyurethane, a second phenolic crosslinking agent and a second aldehyde crosslinking agent; and / or The high temperature gel system comprises water glass and carbon amide.

3. The water blocking system according to claim 2, It is characterized in that The total mass of the dilution-resistant jelly system is calculated as 100%, and the dilution-resistant jelly system includes 0.6 to 1 wt% of the first anionic polyacrylamide, 0.4 to 1 wt% of the first polyurethane, 0.2 to 0.6 wt% of hydroxypropyl methylcellulose, 0.2 to 0.6 wt% of the first phenolic crosslinking agent, 0.2 to 0.6 wt% of the first aldehyde crosslinking agent and the balance of water.

4. The water blocking system according to claim 2, It is characterized in that The weight of the weighted jelly system is calculated as 100%, and the weighted jelly system includes 0.6 to 1 wt % of the second anionic polyacrylamide, 0.6 to 1 wt % of hydroxypropyl starch, 0.2 to 0.6 wt % of phenolic crosslinking agent, 10 to 15 wt % of weighting agent and the balance of water.

5. The water blocking system according to claim 2, It is characterized in that The mass of the high temperature gel system is calculated as 100%, and the high temperature gel system includes 0.6 to 1 wt% of the third anionic polyacrylamide, 0.4 to 1 wt% of the second polyurethane, 0.2 to 0.6 wt% of the second phenol crosslinking agent, 0.2 to 0.6 wt% of the second aldehyde crosslinking agent and the balance of water; and / or The mass of the water glass is taken as 100%, and the amount of the carbonic acid amide is 2 to 4 wt %.

6. The water shutoff system according to any one of claims 2 to 5, It is characterized in that The weight average molecular weight of the first anionic polyacrylamide is 12×10 4 ; and / or the weight average molecular weight of the second anionic polyacrylamide is 10×10 4 ; and / or the weight average molecular weight of the third anionic polyacrylamide is 15×10 4 ; and / or The weight average molecular weight of the first polyurethane and the weight average molecular weight of the second polyurethane are 5500; and / or The first phenolic cross-linking agent and the second phenolic cross-linking agent are hydroquinone; and / or The first aldehyde cross-linking agent and the second aldehyde cross-linking agent are urotropine; and / or The phenolic crosslinking agent is a product obtained by condensation of naphthol and formaldehyde; and / or The weighting agent is potassium chloride.

7. A method for deep source suppression and water blocking in high-angle fractures. It is characterized in that Using the water plugging system according to any one of claims 1 to 6 as a water plugging agent, water plugging is performed in a slug combination manner; 1) The dilution-resistant gel system is used as a pre-slug, injected into the ground, and attached to the subsequent slugs along the way to play a supporting and plugging role; 2) Using the weighted gel system as an intermediate plug, injecting it into the ground to block deep bottom water and suppress the strength of strong bottom water; 3) injecting the high temperature gel system as a post-segment plug to plug near the wellbore and expand the plugging range; 4) Injecting the high temperature gel system as a sealing segment plug to prevent the front segment plug, the middle segment plug and the rear segment plug from spitting back and blocking the wellbore.

8. The method according to claim 7, It is characterized in that The method further comprises step 5), injecting water as a displacement plug.

9. The method according to claim 8, It is characterized in that Taking the total injection volume of the leading slug, the middle slug, the trailing slug, the sealing slug and the displacement slug as 100%, the injection volume of the leading slug accounts for 4 to 8%, the injection volume of the middle slug accounts for 25 to 30%, the injection volume of the trailing slug accounts for 30 to 36%, the injection volume of the sealing slug accounts for 10 to 16% and the injection volume of the displacement slug accounts for 10 to 31%.

10. Use of the water plugging system according to any one of claims 1 to 6 or the high-angle fracture deep source suppression water plugging method according to any one of claims 7 to 9 in water plugging in fracture-vuggy oil reservoirs.

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