CN110714736A - Self-expansion efficient sealing packer - Google Patents

Abstract

The invention belongs to the field of petroleum exploration tools, and particularly relates to a self-expansion efficient sealing packer. The specific technical scheme is as follows: the utility model provides a from inflation packer, includes the parent tube, the parent tube is gone up the cover and is established and meet oil from inflation packing element when meeting water, on the parent tube, a stopper of packing element both ends rigid coupling respectively, stopper and packing element phase separation, be equipped with the liquid that can let the packing element inflation in the stopper, the packing element sets up liquid intercommunication part towards stopper one end, liquid intercommunication part can be launched automatically when the packing element inflation to with the stopper contact, will liquid direction packing element in the stopper. The packer provided by the invention has the advantages of high expansion efficiency of the rubber sleeve, uniform expansion, excellent sealing performance and difficult occurrence of liquid seepage.

Description

Self-expansion efficient sealing packer

Technical Field

The invention belongs to the field of petroleum exploration tools, and particularly relates to a self-expansion efficient sealing packer.

Background

At present, with the continuous development of oil and gas exploitation, the conventional packer cannot meet the exploitation requirement of a complex borehole. The packer can be transported when meeting water and oil to expand. The surface of the packer is sleeved with materials such as rubber which can expand spontaneously when meeting oil when meeting water, and the packer can adapt to various irregular boreholes.

The existing self-expansion packer mainly comprises a self-expansion rubber sleeve and a base pipe, when the rubber sleeve and the base pipe are heated, the rubber sleeve can expand, the base pipe can also deform to a certain degree, and the expansion rates of the base pipe and the base pipe are different, so that a certain gap is formed between the base pipe and the rubber sleeve, and the setting effect of the packer is influenced. In addition, during operation of the rubber tube, the water and oil conditions encountered in each circumferential direction are inconsistent, so that the shrinkage rate of each part of the rubber tube is inconsistent. This not only can lead to the inflation efficiency of packing element, also can make the packing element take place certain distortion, further increases the possibility that the clearance appears between parent tube and the packing element.

Therefore, a packer with high expansion efficiency, uniform expansion and excellent sealing performance is urgently needed.

Disclosure of Invention

The invention aims to provide a packer which is high in expansion efficiency, uniform in expansion and excellent in sealing performance.

In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows: the utility model provides a from inflation packer, includes the parent tube, the parent tube is gone up the cover and is established and meet oil from inflation packing element when meeting water, on the parent tube, a stopper of packing element both ends rigid coupling respectively, stopper and packing element phase separation, be equipped with the liquid that can let the packing element inflation in the stopper, the packing element sets up liquid intercommunication part towards stopper one end, liquid intercommunication part can be automatic intercommunication when the packing element inflation to with the stopper contact, will liquid direction packing element in the stopper.

Preferably, the liquid communication part comprises a plurality of conical bulges arranged at the lower part of one end of the rubber cylinder facing the limiter; the middle part of the end surface of the limiter is provided with a liquid guide film made of waterproof materials facing the bulge, and the hardness of the bulge is greater than that of the liquid guide film and less than that of the walls of other positions of the limiter; the length of the liquid guide film is 1/2-4/5 of the length of the end face of the stopper.

Preferably, a liquid communication channel longitudinally penetrates through the interior of the rubber cylinder, and the protrusions are arranged around openings of the liquid communication channel at two ends of the rubber cylinder.

Preferably, the interior of the stopper is divided into at least 2 chambers arranged along the length direction of the base pipe through a movable baffle plate, the chamber close to the side of the rubber cylinder is filled with liquid capable of expanding the rubber cylinder, a first elastic component is arranged in the chamber far away from the side of the rubber cylinder, one end of the first elastic component is fixedly connected to the movable baffle plate, and the other end of the first elastic component is fixedly connected to the inner wall of the stopper on the opposite side surface of the movable baffle plate; in an initial state, the first elastic component is in a strong compression state.

Preferably, when the movable baffle moves to the end part of the stopper close to one side of the rubber cylinder, the first elastic component is in a weak compression state or a natural state.

Preferably, the inside of the stopper is divided into 3 chambers through two movable baffles, a liquid blocking device is arranged in the middle chamber and comprises a second elastic part fixedly connected to the top of the middle chamber and in a compressed state, the other end of the second elastic part is fixedly connected to an elastic buckling part in a contracted state, a clamping groove in a shape corresponding to the buckling part is formed in the wall of the base tube, and the clamping groove is located at the position of the middle chamber, corresponding to the buckling part, of the moving tail end.

Preferably, the position of the base pipe sleeved with the rubber cylinder is stepped, the depth of the stepped recess to the interior of the base pipe is 1/6-1/4 of the inner diameter of the base pipe, and the shape of the rubber cylinder corresponds to that of the base pipe; the liquid communication channel extends in the direction of the interior of the base pipe at the recess.

The rubber cylinder is made of rubber which can expand automatically when meeting oil, and the components of the rubber cylinder comprise ferric oxide.

Preferably, the formula of the rubber comprises the following components in parts by weight: 15-18 parts of ethylene propylene diene monomer, 2-5 parts of carbon black, 1-3 parts of stearic acid, 1-3 parts of calcium oxide, 3-5 parts of ferric oxide, 6-8 parts of active zinc oxide, 0.04-0.3 part of zinc dimethyldithiocarbamate, 0.5-1 part of antioxidant RD and 0.01-1 part of sulfur.

Preferably, the preparation method of the rubber comprises the following steps:

(1) plasticating the ethylene propylene diene monomer on an open mill until the surface is smooth;

(2) adding stearic acid, calcium oxide, ferric oxide and active zinc oxide for mixing;

(3) then adding zinc dimethyldithiocarbamate and an anti-aging agent RD for mixing;

(4) and adding sulfur, and vulcanizing for 1-1.5 h under the conditions of 160-190 ℃ and 8-12 MPa.

The invention has the following beneficial effects: the base pipe and the rubber cylinder are arranged in a step shape which is combined more tightly, so that liquid seepage caused by slight deformation is avoided. Meanwhile, two ends of the rubber cylinder are respectively provided with a limiter filled with liquid, and the rubber cylinder is correspondingly provided with a liquid communicating component; the lateral expansion of the rubber cylinder is limited, and the part of the rubber cylinder which can contact with the liquid later can be rapidly contacted with the liquid to expand. The packer provided by the invention has the advantages of high expansion efficiency of the rubber sleeve, uniform expansion, excellent sealing performance and difficulty in seepage and the like.

Drawings

FIG. 1 is a schematic structural diagram of an initial state of the present invention;

FIG. 2 is an enlarged view of FIG. 1 at A;

FIG. 3 is a schematic structural view of a use state of the present invention;

fig. 4 is an enlarged view of fig. 3 at B.

Detailed Description

As shown in fig. 1 and 3, the self-expansion packer comprises a base pipe 10, wherein a self-expansion rubber tube 20 which can be self-expanded when encountering oil when encountering water is sleeved on the base pipe 10, two ends of the base pipe 10 and two ends of the rubber tube 20 are fixedly connected with a stopper 30 respectively, and the stopper 30 is separated from the rubber tube 20.

It should be understood that, in the initial installation state, the rubber cylinder 20 is tightly sleeved on the base pipe 10, the stopper 30 is fixedly connected to the base pipe 10, and a certain gap exists between the rubber cylinder 20 and the stopper 30. The glue cartridge 20 expands both laterally and longitudinally when it self-expands in water or oil. When the stopper 30 is expanded in the transverse direction, the stopper 30 provides a pressing force to the rubber tube 20 in the transverse direction, so that the rubber tube 20 is expanded in the longitudinal direction to achieve sealing. Because the water or oil quantity encountered at each circumferential position of the rubber cylinder 20 is not necessarily the same, the expansion conditions at each position are different, and a sealing state cannot be quickly formed; meanwhile, the rubber cylinder 20 is easily twisted to a certain degree relative to the base pipe 10 due to the inconsistent expansion speed at each position, so that a gap is formed between the rubber cylinder 20 and the base pipe 10, and the sealing failure is caused.

Therefore, the stopper 30 is filled with a liquid that can expand the rubber cartridge 20. The liquid is matched with the material of the rubber tube 20, and if the rubber tube 20 is made of water-swelling rubber, such as a water-swelling water stop strip of the Henghui rubber product Co., Ltd, the liquid is clear water; if the rubber cylinder 20 is oil-exposed self-expanding rubber, such as oil-exposed self-expanding rubber cylinder of Jing county Pingxin rubber and plastic processing department, the liquid can be gasoline or diesel oil. The rubber tube 20 is provided with a liquid communication part towards one end of the stopper 30, and the liquid communication part can be automatically started when the rubber tube 20 expands to be in contact with the stopper 30, so that the liquid in the stopper 30 is guided to the rubber tube 20. It should be understood that after the rubber cylinder 20 is self-expanded, the gap between the rubber cylinder 20 and the stopper 30 is compensated by the expanded rubber cylinder 20, and the liquid communication device on the rubber cylinder 20 is in contact with the stopper 30, so as to directly guide the liquid, such as oil or water, inside the stopper 30 to the rubber cylinder 20, help the rubber cylinder 20 to rapidly contact the liquid everywhere, and achieve rapid completion of expansion and sealing everywhere.

Preferably, as shown in fig. 2, the liquid communication component includes a plurality of conical protrusions 22 disposed at a lower portion of one end of the rubber cylinder 20 facing the stopper 30; the middle part of the end surface of the limiter 30 is provided with a liquid guide film 35 made of waterproof materials facing the bulge 22, and the hardness of the bulge 22 is greater than that of the liquid guide film 35 and less than that of the walls of the rest positions of the limiter 30; the length of the liquid guide film 35 is 1/2-4/5 of the length of the end face of the stopper 30.

The description will be made with the top, bottom, left and right in fig. 2 and 4 as the orientation. It should be understood that the protrusion 22 is a part of the rubber cylinder 20, and when the rubber cylinder 20 swells when contacting oil, water, etc., since the protrusion 22 is located on the end surface of the rubber cylinder, it will not contact oil, water, etc. temporarily, and will not swell, and still maintain a sharp point. When the rubber cylinder 20 expands, the protrusion 22 moves upward left along with the rubber cylinder and is rapidly contacted with the liquid guide film 35, the liquid guide film 35 can be made of waterproof materials such as plastic films resistant to high temperature of more than 200 ℃, and the waterproof materials are broken under the action of the protrusion 22, so that liquid in the stopper 30 flows out and is contacted with the rubber cylinder 20, and the rubber cylinder 20 is assisted to expand rapidly. The liquid guiding film 35 remains on the stopper 30 after puncturing, and is not shown in fig. 4 because it has only one film, occupies a small volume and can be ignored after puncturing. While the projections 22 follow the rubber sleeve 20 expanding upwards, which cannot be seen in fig. 4.

More preferably, a liquid communication channel 21 is longitudinally arranged in the rubber cylinder 20 in a penetrating manner, and the protrusion 22 is arranged around the openings of the liquid communication channel 21 at the two ends of the rubber cylinder 20. Under this kind of setting, the inside liquid of stopper 30 not only can directly be absorbed by the terminal surface of packing element 20, can also get into inside packing element 20 through the inside liquid intercommunication passageway 21 of packing element 20, and packing element 20 both ends set up same stopper 30, and both ends intercommunication further accelerates the inflation of packing element 20, also guarantees the even degree of inflation everywhere. The liquid communication channel 21 inside the rubber tube 20 is automatically pressed closed after expansion, so that the liquid communication channel 21 is not shown in fig. 3 and 4.

More preferably, the stopper 30 is divided into at least 2 chambers in the horizontal direction by a movable baffle, the chamber close to the side of the packing element 20 is filled with a liquid capable of expanding the packing element 20, a first elastic component 32 is arranged in the chamber far away from the side of the packing element 20, one end of the first elastic component 32 is fixedly connected to the movable baffle, and the other end of the first elastic component is fixedly connected to the inner wall of the stopper 30 on the opposite side of the movable baffle. In the initial state, the first elastic component 32 is in a strong compression state, and the elastic potential energy is maximum. When the movable baffle moves to the end of the stopper 30, the first elastic component 32 is in a weak compression state or a natural state, so that the movable baffle can move to the end of the stopper 30, and the liquid in the stopper 30 can be rapidly and completely introduced into the rubber cylinder 20.

More preferably, the inside of the stopper 30 is divided into 3 chambers by two movable baffles, a liquid blocking device is arranged in the middle chamber, the liquid blocking device includes a second elastic component 33 fixedly connected to the top of the middle chamber and in a compressed state, the other end of the second elastic component 33 is fixedly connected to an elastic buckling component 34 in a contracted state, a clamping groove 12 corresponding to the buckling component 34 in shape is arranged on the tube wall of the base tube 10, and the clamping groove 12 is located at a position corresponding to the middle chamber motion end buckling component 34. As shown in fig. 2 and 4, in the initial state, the first elastic member 33, such as a spring, and the intermediate chamber are limited to the space on the left side of the stopper 30 by the liquid guide film 35 and the liquid. As the bulge 22 pierces the liquid guiding film 35, the liquid flows out, and the first elastic member 33 releases the elastic potential energy to push the middle chamber to the right. Since there is no opening in the bottom of the stopper 30 except the slot 12, the locking member 34 is always prevented from being released and confined within the middle chamber during pushing. When the middle chamber is pushed to a position above the corresponding position of the slot 12, the second elastic member 33, such as a spring, pushes the locking member 34 into the slot 12, and the locking member 34 is released and locked with the slot 12. Of course, there may be some liquid in the slot 12 at this time, but the fit between the locking member 34 and the slot 12 is not affected.

More preferably, the base pipe 10 is provided with a rubber cylinder 20 in a stepped shape, the depth of the stepped shape sunken into the base pipe 10 is 1/6-1/4 of the inner diameter of the base pipe, and the rubber cylinder 20 corresponds to the base pipe 10 in shape. The base pipe 10 and the rubber cylinder 20 which are arranged in a stepped manner have larger contact surface, are combined more tightly and are not easy to leak. In this arrangement, the liquid communication channel 21 can be extended into the stepped recesses in the rubber tube 20 to help the later liquid contacting portion to quickly contact the liquid and expand.

In order to increase the expansion rate of the rubber cylinder 20 and achieve quick and efficient seat sealing, it is preferable that the rubber cylinder 20 is made of a special self-expanding rubber which can expand when exposed to oil. The formula of the self-rubber capable of being contacted with oil is as follows: 15-18 parts of ethylene propylene diene monomer, 2-5 parts of carbon black, 1-3 parts of stearic acid, 1-3 parts of calcium oxide, 3-5 parts of ferric oxide, 6-8 parts of active zinc oxide, 0.04-0.3 part of zinc dimethyldithiocarbamate, 0.5-1 part of antioxidant RD and 0.01-1 part of sulfur.

The rubber is vulcanized under the conditions of 180 ℃ and 10MPa, and the preparation method comprises the following steps:

(1) plasticating ethylene propylene diene monomer rubber on an open mill until the surface is smooth, adjusting the roll spacing of the open mill to be 0.3mm, adding carbon black, and mixing for 1-2 min;

(2) adjusting the roller spacing to be 2.5mm, adding stearic acid, calcium oxide, ferric oxide and active zinc oxide, and mixing for 1-2 min;

(3) adding zinc dimethyldithiocarbamate and an anti-aging agent RD, and mixing for 6-10 min;

(4) finally, adding sulfur, and vulcanizing for 1-1.5 h at 180 ℃ and 10 MPa.

To better demonstrate the effect of the rubber, the following is presented in detail. Groups 17 of rubbers were prepared as experimental groups in the manner described above. Wherein the ethylene propylene diene monomer used in each group is 16 parts, the stearic acid accounts for 15% of the mass of the ethylene propylene diene monomer, and the dosage of the antioxidant RD accounts for 3% of the mass of the ethylene propylene diene monomer. The formulations of the various groups of rubbers are shown in Table 1. In table 1, "zinc dimethyldithiocarbamate: the sulfur means the mass ratio of the two. It should be understood that table 1 is an example only, and not that only the inventors have conducted the experiments in table 1.

Table 1 table for showing specific formula of each rubber group

The common oil absorption rate, the expansion rate and the mechanical property of each group of rubber are respectively tested under the same condition, and each group is provided with 3 repetitions. The method for measuring the oil absorption rate and the expansion rate comprises the following steps: and (3) completely soaking the dried rubber in the oil to be absorbed until the weight and the volume of the rubber are not changed, taking out the rubber, and comparing the weight and the volume difference of the rubber before and after oil absorption. The unit of oil absorption is: g/g, i.e. the maximum oil absorption per gram of rubber. The results are shown in Table 2.

TABLE 2 comprehensive properties of various rubbers

Claims (10)

1. A self-inflating packer, comprising: including parent tube (10), parent tube (10) are gone up the cover and are established from inflation packing element (20), parent tube (10) are gone up, stopper (30) of packing element (20) both ends rigid coupling respectively, stopper (30) and packing element (20) phase separation, be equipped with the liquid that can let packing element (20) inflation in stopper (30), packing element (20) set up liquid intercommunication part towards stopper (30) one end, liquid intercommunication part can be in packing element (20) inflation to with stopper (30) contact time automatic intercommunication, will liquid direction packing element (20) in stopper (30).

2. The self-inflating packer of claim 1, wherein: the liquid communication component comprises a plurality of conical bulges (22) which are arranged at the lower part of one end of the rubber cylinder (20) facing the limiter (30); the middle part of the end face of the limiter (30) is provided with a liquid guide film (35) made of waterproof materials facing the bulge (22), and the hardness of the bulge (22) is greater than that of the liquid guide film (35) and less than that of the rest positions of the limiter (30); the length of the liquid guide film (35) is 1/2-4/5 of the length of the end face of the stopper (30).

3. The self-inflating packer of claim 2, wherein: a liquid communication channel (21) longitudinally penetrates through the interior of the rubber cylinder (20), and the protrusions (22) are arranged around openings of the liquid communication channel (21) at two ends of the rubber cylinder (20).

4. The self-inflating packer of claim 1, wherein: the interior of the stopper (30) is divided into at least 2 chambers arranged along the length direction of the base pipe (10) through a movable baffle, the chamber close to the side of the rubber cylinder (20) is filled with liquid capable of expanding the rubber cylinder (20), a first elastic component (32) is arranged in the chamber far away from the side of the rubber cylinder (20), one end of the first elastic component (32) is fixedly connected to the movable baffle, and the other end of the first elastic component is fixedly connected to the inner wall of the stopper (30) on the opposite side surface of the movable baffle; in an initial state, the first elastic member (32) is in a strongly compressed state.

5. The self-inflating packer of claim 4, wherein: when the movable baffle moves to the end part of the stopper (30) close to one side of the rubber cylinder (20), the first elastic component (32) is in a weak compression state or a natural state.

6. The self-inflating packer of claim 5, wherein: stopper (30) inside divide into 3 cavities through two adjustable fender, sets up in the middle cavity and hinders the liquid ware, hinder the liquid ware including rigid coupling in middle cavity top, be in compression state second elastomeric element (33), second elastomeric element (33) other end rigid coupling is in the elasticity buckle spare (34) of contraction state, set up on base tube (10) pipe wall shape with draw-in groove (12) that buckle spare (34) correspond, draw-in groove (12) are located the middle cavity motion end corresponds buckle spare (34) position.

7. The self-inflating packer of claim 1, wherein: the base pipe (10) is provided with a stepped rubber sleeve (20) in a sleeving manner, the depth of the stepped recess towards the interior of the base pipe (10) is 1/6-1/4 of the inner diameter of the base pipe, and the rubber sleeve (20) corresponds to the base pipe (10) in shape; the liquid communication channel (21) extends in the direction of the interior of the base pipe (10) at the recess.

8. A self-expanding packer according to claims 1-7, characterised in that: the rubber cylinder (20) is made of rubber which can expand automatically when meeting oil, and the rubber comprises iron oxide.

9. The self-inflating packer of claim 8, wherein: the formula of the rubber comprises the following components in parts by weight: 15-18 parts of ethylene propylene diene monomer, 2-5 parts of carbon black, 1-3 parts of stearic acid, 1-3 parts of calcium oxide, 3-5 parts of ferric oxide, 6-8 parts of active zinc oxide, 0.04-0.3 part of zinc dimethyldithiocarbamate, 0.5-1 part of anti-aging agent RD and 0.01-1 part of sulfur.

10. The self-inflating packer of claim 9, wherein: the preparation method of the rubber comprises the following steps:

(1) plasticating the ethylene propylene diene monomer on an open mill until the surface is smooth;

(2) adding stearic acid, calcium oxide, ferric oxide and active zinc oxide for mixing;

(3) then adding zinc dimethyldithiocarbamate and an anti-aging agent RD for mixing;

(4) and adding sulfur, and vulcanizing for 1-1.5 h under the conditions of 160-190 ℃ and 8-12 MPa.

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