At present, the oil pump plunger and pump cylinder used in each oil field in our country are mainly gap-sealed. In order to solve the sand control problem of the pump, an annular groove is machined on the plunger, and a removable fixed valve is installed for convenient maintenance of the pump, or a sand tank is installed on the fixed valve. In order to solve the problem of wear-resistant, pump cylinder with special heat treatment of alloy steel, and then honing, or 45 steel carbonitriding, and honing processing; plunger alloy steel hard chrome plating, or spray-resistant wear-resistant alloy, and then Grinding. Even with these measures, the pump sand and wear resistance is not satisfactory. The reason is that the gap seal caused by the fine sand with plunger movement into the gap between the pump cylinder and the plunger to produce grinding effect, and as the use of the cycle, wear increased, leakage increased, until scrapped. First, the development of the newly developed sand-control gapless seal pump successfully solved the pumping pump the existence of the above problems, that is, without gap seal instead of gap seal; plunger length is shorter, only the gap seal plunger length of half; column The plug body is fitted with an improved Sturgeon inflatable seal. Medium hardness wear ring and high hardness wear ring. These three kinds of sealed components by the wear-resistant, low coefficient of friction, good elasticity of the material by special processing made to ensure that the pump down from the pump to work is always in the gap state. Oil and sand mixture as the working medium (Liaohe Oilfield crude oil, 80 mesh sieve sand accounted for 5%) to do the uphole simulation test. At 20MPa, the suction resistance of only 157 +20 N, filled with a coefficient of 1, which is expected to increase pump efficiency of 20% to 50%. Simulated experiments were observed, three kinds of seal structure design and components of the special lip design, to prevent the micro-sand into the plunger 2 cylinder friction pair. Due to the short plunger body mounted on the three kinds of seals are swollen, so the pump cylinder and plunger body processing accuracy is greatly reduced. Test, the plunger speed 1m / s, continuous suction operation 30d, pump cylinder without scratches, trace wear, the surface uniform light. According to this situation, it is estimated that when the downhole operation is in bad condition, the life span of the pump can reach 215-3a, and the pump barrel is evenly worn, and the inner surface of the drum of the drum-shaped cylinder will not be eccentric worn as the gap seal. In addition to the plunger body installed three kinds of seals, there are two swimming valve and a special rotary valve cover, the body processing sand control tank, will invade the fine sand into the sand control tank. In the simulation test, there is a trace of sand in the groove. The upper part of the plunger body is made of a rotary valve cover and the lower part of the rotary valve cover of the pump barrel is used for swirling the crude oil drawn into the pump by the powerful suction force of the plunger, The sand in the rapid pumping to the pump. Due to the short plunger, under the same anti-punching distance, the pump barrel is shortened by 700-800mm. When the pump is to be repaired, only three kinds of seals on the plunger are replaced, and the plunger body can be used repeatedly. Second, the technical points 1, pump no gap seal and high pump efficiency installed on the plunger 3, a reasonable structure of swollen seal placed in the plunger position, the composition of the seal material selection, machining accuracy and processing technology are Pump to ensure long-term operation has always been to maintain gap-free, wear-resistant, low friction coefficient and efficient long-life work of the key. Figure 1 shows the position of various seals and travel valves on the plunger. 2, 3 for the middle hardness of the seal ring; pieces 4, 5, 6 for the improved Stewart tank seal; pieces 7, 8 for high hardness hard seal expansion ring; piece 2 has 2, with medium hardness cast iron Made of; piece 3 made of spring steel. Two outer ring openings are staggered 180b when installed, the inner ring openings are offset from the outer ring openings by 90b, and the three rings are fixed with pins. The outer ring is tightly attached to the inner surface of the pump barrel under the combined effect of its own expansion force and inner ring expansion force. Operation, expansion ring is not only good axial seal, and radial seal Ye Hao, it prevents the micro-sand into the axial friction pair, but also to prevent the micro-sand into the inner gap of the inner ring 3 will not hinder the expansion ring operation breathing. Pieces 4, 5 and 6 are made of wear-resistant metal or non-metallic organic material filled inside, have good abrasion resistance and small friction coefficient, and the structure itself can ensure that the sealing has certain expansibility. In order to prevent the intrusion of fine sand and other substances inside the seal, pieces 5 and 6 are installed on both sides of the retaining ring 4, which effectively prevent sand and other intrusion inside the sealing body and affect the tension. 7,8 structural pieces 2,3 with hardness wear ring, only the outer ring 7 made of special alloy steel heat treatment, the surface hardness is less than the cylinder barrel surface hardness, good elasticity, good wear resistance, small friction coefficient , To achieve the seal is its main function. These three kinds of seal structure to ensure uniform inner wall of the cylinder bore expansion and reliable radial shaft seal performance, to ensure that the suction vacuum and high fill factor, thus ensuring high pump efficiency. 2, Active sand control and long-life plunger body installed on the three kinds of swollen seal and seal the outer lip special lip design to prevent the sand can not enter the friction pair from the grinding effect, greatly reducing the plunger and pump cylinder Wear, that is, will not weaken the suction capacity. Judging from the actual simulation, the multi-channel sand-based inflatable sealing has played a very good role in sand control, running a month after the plunger body ring groove with only a small amount of sand, indicating the plunger body to open Sand control tank and the body itself has played a role in sand control. Three kinds of seal structure design and position on the plunger body to ensure that the pump has a strong suction and discharge capacity, high oil into the oil flow in the fixed valve cover and the upper part of the floating valve valve open Make spiral groove, see Figure 2, Figure 3, so that the inlet and outlet flow was a strong cyclone, fine sand sediment was discharged too late. Will prevent the fine sand into the movement deputy and the rapid extraction of sand to the pump can be seen as active sand control, sand control effect than the existing pump on the pure sand and sand tank is much better. The pump has long life under harsh conditions downhole from the standpoint of active sand control and the low coefficient of friction, high wear resistance and low suction resistance between the pump barrel and the plunger during the pumping operation. 3, a reasonable downhole technology In the development of new structure of the pump at the same time, two pilot wells down process. (1) The pump cylinder and the plunger respectively go down, that is, the pump cylinder goes down along with the tubing string, and the plunger goes down with the sucker rod column. Due to the difficulty of this pump plunger down, it is recommended to take two ways: First, the plunger is contained in a special sheath, the sheath has a claw, when the plunger and sheath down to the mouth of the barrel , The sheath will be automatically stuck in the mouth of the pump barrel set the default card holder, the plunger can be successfully down into the pump cylinder. The second is a special type of cement to all the way in the fully closed (sealed expander outer diameter smaller than the outer diameter of the plunger body) seal the plunger with the sucker rod down well, the plunger into the pump After the cylinder and ordinary pump to adjust the punching distance, because the improved Stewart tank seal is only temporary pressure type, after the well will soon achieve sealing and sand blocking function. While the rest of the seals in the plunger pump into the cylinder 2 ~ 7d also all open. This cement in the well of petroleum gas and crude oil erosion, loss of part of the cementation strength, the elastic seal expander ring by the expansion of the role was opened. (2) Connect the pump plunger and pump barrel with the dual card disconnect and release sleeve. Before the downhole, connect the lower part of the disconnector and the plunger to the pump barrel of the conical mouth, and then release the sleeve and the pump barrel to release the sleeve tubing string into the well together. After the well is set up, The upper part of the device is connected with the sucker rod into the tubing, so as to realize the overall pump down. When the pump is overhauled, the sucker rod column can be lifted up to the upper part of the pump cylinder to release the sleeve part, and the release sleeve can force the double card of the detachable connector to be folded up so that the upper body and the lower body of the detachable device are disengaged to achieve the lifting column operation and the lift pump.