Research And Experiment On Technology Of Combination Huff-puff For Enhanced Heavy Oil Recovery In H003 Well Field Of Xinjiang

Xinjiang H003 well is located in the northwestern margin of Zhungaer Basin,with more than 4000×10~4t mature geological reserves.It is the key exploration and development heavy oil block of Xinjiang Oilfield,beginning to be developed in 2009.The formation pressure of H003 well field is about 4.65MPa.The temperature of the reservoir is about 24?,and the depth of the reservoir is about 490m.The viscosity of the crude oil is about 30000mPa?s.It belongs to the shallow special heavy oil reservoir.The heavy oil in the development process showed low efficiency of steaming,low cycle oil production and other problems.Aiming to the existing problems,research and experiment on combination huff-puff technology for enhanced heavy oil recovery is developed by reservoir engineering methods,under the condition of fully understanding the reservoir characteristics of the well area and the viscosity-temperature characteristics,rheological properties and high-pressure properties of heavy oil.It is high-pressure degreasing system and nitrogen-assisted high-temperature steam for heavy oil stimulation.The viscosity reducing agent can reduce the start-up pressure of the steam injection and increase the flow ability of the heavy oil in the formation.Nitrogen can expand the radius of action of the viscosity reducer to supplement the formation energy and the sweep coefficient of the steam.The viscosity reducer and nitrogen assisted steam stimulation effectively improve the H003 well heavy oil recovery and increase the single well production.Simultaneously,physical modeling and numerical simulation experiments are carried out.The on-site research and optimization of process parameters are completed.And preferable system for reducing the mud thinner for the crude oil in H003 well field is confirmed,with steam injection strength about 165t/m,Nitrogen injection strength about2100Nm~3/m,viscosity reduction about 40t/m in a throughput cycle.Through field verification,the technology has a good development effect on the heavy oil reservoir in H003 well field.Through the single well geological model,degreasing and nitrogen assisted after steaming,the well bottom temperature and the effective spread of steam in the well are significantly greater than those of the original steam injection.Production cycle is extended significantly.From the test of 29 wells,An average individual oil production increases 219t,saving steaming 200t in a throughput cycle.According to 791yuan/t operating costs,the Input-output ratio is 1:2.82,with significant benefits.New technologies for enhanced recovery are developed for the H003 well and other similar wells of Xinjiang oil field.Simultaneously,the amount of steam injected is reduced effectively,meant a great deal for energy-saving?emission reduction and reducing costs to increase benefit.