人工舉升產(chǎn)品的問(wèn)題和前景

1、The summary of artificial lift problem and solutionZHANGXIYUWhen the pressure of the reservoir fluids within the reservoir are less than, or change with time to be less than the hydrostatic head pressure of the total produced fluids from the reservoir to the surface production wellhead, the fluids w

2、ill not flow. To get fluid to the surface, we need some kind of artificial lift. There are varieties of artificial lift including ESP lift, sucker rod lift and PCP pump lifting. The rapid development of oil industry creates a lot of technology innovation chance for these artificial lift. More and mo

3、re artificial lift vendors put more fund in the research and development of artificial lift. Even so, many application problems still exist. Every artificial lift has its own advantage and disadvantage, and each one has its application range in the oilfield. The article will give a guideline for the

4、 typical artificial lift. The picture-1 shows the percentage of these lift method of 2000.Picture-1 Artificial lift methods of 20001. ESP (electrical submersible pump)There are about 70,000 ESP all over the world。ESP is a very popular artificial lift method when pumping big flow rate fluid in the bi

5、g casing size well. And also, the ESP is a main artificial lift method on the offshore due to the unique features on offshore all over the world. There are many advantages, but there are some application problems and some solution applied is not very ideal.1.1 Problem (1) High reservoir temperature

6、problem.(2) High gas content problem or high GOR (3) Deeper well problem(4) High thicker oil and scale problem 1.2 Solution There are some ESP application problems faced in ESP pump industry and some measures have already been taken to decreased the trouble. Technology innovation in pump industry in

7、cluding material improvement、electrical、pump structure etc make the ESP application in harsh reservoir condition feasible. (1) Solution for the high temperatureThe typical normal reservoir temperature which is below 100 could install the conventional ESP pump in the well-bore without any modificatio

8、n. But if the reservoir temperature is more than 100, the ESP selection and application will be another story. We experience some high reservoir temperature and adopt some measures.ü Adopt higher-class rubber materialü Adopt different structure of the motor such as adding a circulating imp

9、eller at the bottom of the motor ü Improve the fluid velocity passing the motor housingü Size bigger horsepower motor (2) High gas content or high GOR Gas has been an annoying problem in ESP application. When the reservoir pressure is lower than bubble point pressure, the gas accumulation

10、in the passage of the pump impeller is formed and it will take up the space of the passage in the impeller and block the fluid. Then the gas locking occurs. Right now there are several methods applied the ESP application.ü Adopt tandem gas separator or high efficiency gas separator.ü Adopt

11、 PGP by Powerlift patent. The principle is to mix the gas into the liquid and homogenize the mixture of the gas and fluid, the fluid to be pump is similar to a single phase. ü Install PGP and gas separator together to minimize the gas problem.ü Install the reverse shroud in the well-bore.

12、The principle is to force the fluid go downward and come into the pump intake, but the gas will go upward along the shroud due to buoyancy. The gas is separated by this method. (3) Deeper well solution The pump depth of the ESP has been becoming deeper and deeper as the technology improvement recent

13、ly. Powerlift has already lift 3000meters fluid. But there are some measures to be solved.ü The burst pressure of the ESP pump housing have to be considered.ü The down-hole pressure and temperature is becoming higher and higher. The rubber material of the motor and protector should be cons

14、idered.(4) High thicker oil and scale problem The problem oil has been problem especially thicker oil. When the ESP pump lifts this kind of oil, the friction between the thick oil and pump impeller passage will increase the load of the motor and it finally cause the overload of the motor.ü Enla

15、rge the width of the impeller passage and change the angle of the hydraulic.ü Improve the anti-resist coat of the pump impeller and reduce the friction.ü Install the cable protector and reduce the effect of the measure which is used to reduce the thick concentration of the oil.ü Impro

16、ve the motor horsepower and strength the ability of reducing the viscosity of the oil by stirring of the ESP pump.  ü Installing VSD to improve the adaptbility of the ESP.2. ROD (Sucker rod pump or beam pumping unit)Rod is a short of Beam Pumping unit/ Sucker Rod Pumps (Rod Lift). There ar

17、e about 500,000 beam pumping unit all over the world (Picture 3 shows the beam pumping unit). The advantage of this pump could be described as following: ü High system efficiencyü Optimization controls availableü Economical to repair and serviceü Positive displacement/strong draw

18、downü Upgraded materials can reduce corrosion concernsü Flexibility - adjust production through stroke length and speedü High salvage value for surface unit and downhole equipment Picture 3 beam pumping unitBut there are also some disadvantages of this lift such as the pump is limited

19、 to relatively low production volumes, less than 1,000 barrels per day.2.1 Problem The main problem of the beam pumping unit lies in the fact that the energy-consuming of the unit is amazing due to enormous number. 2.2 Solution If the energy-consuming of unit is decreased, the problem of the pumping

20、 unit will solve. The energy-saving pumping unit is developed and install in the oilfield all over the world in these years.There are several methods to be used to solve the problem.ü Adopt the energy-saving pumping unit. Such as offset-wheel beam pumping unit, downward barbell pumping unit，etc

21、. Picture 4 offset-wheel pumping unitü Energy drag device. There are two kinds of device could be used including energy-saving control panel and energy-saving motor 3. PCP (Progressing cavity pump)There are about 40,000 PCP units all over the world. PCP application is only second to the ESP in

22、the world. But the application of PCP for artificial lift is still new compared to other technologies. The technology is advancing rapidly and that, combined with new techniques which are learned empirically, continually expands the range of applications.3.1 Problem(1) The application range of the P

23、CP(2) Short rotor life (3) corrosion and abrasion problem in harsh enviroment3.2 Solution(1) The factor of increasing the range of application of PCPs is mainly dependant on the technology innovation of the rubber material. The ex-factory rubber material is using and testing the material to ensure the rubber is conformed to the reservoir conditions. It will ensure the rubbers still offer the best combinations of mechanical properties and resistance tochemical attack for most applications.(2) The rotor supplier tries their best to improve the rotor life by doing novel