Offshore High Water Cut Oilfield Downhole Oil Water Separation And Reinjection Technology Research And Application

With the further development of offshore oil field,especially after oilfield has entered the middle and late mining,in order to improve the output of crude oil,oil is widely used in strong water flooding technology,resulting in the water content in oil wells increased year by year,the mining cost is getting higher and higher.A large number of output water treatment to bring a lot of negative impact on the environment.Oilfield has entered into high water cut period,often appear a series of contradictions,but for mining underground crude oil or stable oil production,into the most during the period of high water cut oilfield using extract production.Regional provided production of liquid liquid producing capacity was greatly increased the production block,the system brings pressure to the production processing,even more than the platform and the processing capacity of the system,but also increases the offshore oil field energy-saving emission reduction pressure.How to deal with the large quantities of water produced in the production of liquid extraction in high water cut stage has become an important issue in the field of oilfield development.When the oilfield has entered the high water cut stage,in order to increase the crude oil output and overall economic efficiency,the downhole oil-water separation system of this new technology,the technology has been attached great importance in the petroleum industry and development technology in the field,is the oil stabilizing oil production and controlling water and develop the technology development direction of.Downhole oil-water separation system can make high water cut crude oil separation of oil and water directly in the underground,isolated from the water is injected directly into the other injection water or waste oil,after the separation of containing a small amount of water in the crude oil is lifted to the surface.Application of this technology can save the energy of the mixed liquid and a lot of water injection,reduce the sewage treatment capacity,save the production cost,extend the production cycle of the oil well,and achieve the purpose of enhancing oil recovery.Aiming at the existing face of downhole oil-water separation and Reinjection Technology Problems and offshore oil field characteristics,were studied using "downhole oil/water separation and Reinjection Technology to improve the operation effect of oilfield development,theoretical and experimental research based on the first pipe type oil-water separator for downhole oil-water separation,combined with the structural characteristics of a new type of pipe separator,with injection wells mining process column system of Y oilfield downhole oil-water formation and the sea to separation,and a breakthrough in the downhole parameters monitoring and control technology,realize output fluid in the wellbore oil water separation,most of the water separated(oil content rarely)injected into the same well another layer,and oil rich fluid is pumped to the ground operation process.This research is a new research direction for oil and water separation technology in offshore oilfield.The system has the advantages of large capacity,compact structure,and its application will bring obvious economic benefits and social benefits to the offshore oilfield.Based on the study of the mechanism,numerical simulation and laboratory experiment,the research and development of a new type of oil and water separator for oil well is developed.A new pipe type oil-water separator changed the original hydraulic swirling chamber structure and lateral entrance way,and in the pipe directly produce the vortex were isolated by using the axial inlet and the structural design can greatly reduce the diameter of the separator,separator processing capacity is 1200m3/d.The maximum outer diameter only for 130mm,and design and manufacture of processing amount in the range of sample series of 300?1200m3/d interval.The different parameters of indoor simulation experiment on the separation efficiency of the underground pipe type oil-water separator,in the oil-water separation processing volume reached 1200m3/d shunt ratio(injection volume/total output)greater than 60%,water reinjection of oil content<950mg/L meet design index of requirements.In order to grasp the downhole oil-water separation device in the dynamic change of underground established underground parameter monitoring and dynamic control system,realizes adjustment of underground fluid production and water injection rate,ensure that all parameters and design parameters match,and improves the system's efficiency and stability.According to the structure characteristics of the new type of pipe separator,the structure of Y type downhole oil water separation technology in the same well is formed,which is suitable for offshore oil field.The process using a Y type joint is established to separate oil and water separation of single channel,one side of the connecting pipe type oil-water separator,pipe type oil-water separator inlet end is connected with a electric submersible pump,the utility model has the advantages of compact structure,wellbore has enough space for a flow channel is established,which greatly improves the processing quantity of oil and water.Downhole oil-water separation and recycling technology of conventional electric pump lifting system and combining with the downhole oil-water separation technology improved,with well separated after the water back into another water or waste layer or another lifetime production wells producing interval,forming wells and injection production system.Development of the system has the following characteristics:(1)using liquid-liquid hydrocyclone separation device to achieve efficient separation of oil and water downhole,the separation device is small in size,no moving parts,reliable performance,easy maintenance.(2)according to the specific circumstances of the production wells to design,can achieve different well depth requirements.(3)with the continuity,a high separation efficiency,oil and water separation device can completely separate the oil droplets of 60 m or more,the diameter of 40 m to 50 m range of oil droplets still have a high separation efficiency.Complete the design of downhole oil-water separation process pipe column and the research of the matching system,and design the implementation scheme and the successful implementation of CFD11-2-A17 oil water separation.In this paper,the downhole oil-water separation technique can avoid a lot of ground water production processing,reduce the production cost,and injected water can supplement the formation energy,slow decline of real estate pressure;at the same time,the conventional pump lifting system and improvement of the downhole oil-water separation device development and the downhole monitoring and control system research,the technology for oilfield long-term stable provides strong technical support is oilfield development especially in high water cut oilfield stable production in the middle and later period of the development of an effective means,is of practical significance.Through the study of this paper and for offshore oilfield with high water cut downhole oil-water separation and reinjection technology implementation was explored and subsequent sea high water cut oilfield downhole oil-water separation reinjection promotion laid the foundation.Through continuous development of downhole oil-water separation and recycling technology and perfect,for the stable production of offshore oil field provides strong technical support.