Layered Water Injection Technology In High Temperature High Pressure And Low Permeability Reservoir Of Block Fan18-3

In our country, low permeability oilfield is distributed very widely. About 10% of total petroleum-in-place in land oilfield is low permeability, and over half of explored reserves which are not developed are low permeability reserves. With development of oilfield in-depth, high temperature, high pressure and low permeability reservoir which is buried deeply and hard production is becoming a new growth point for available reserve. At present, water injection of low permeability still introduces routine layered water injection technology which realizes separate flood by using Y341, Y344 packer. However, under the circumstance of deeply buried reservoir, high temperature reservoir, low permeability reservoir and high pressure of water injection, routine layered water injection technology has many unadapted effects: temperature and pressure effects which are very obvious result in long distance of water injection string and packer disabled; qualification rate of layered water injection is low; the life of string is shortness, and sometimes repair cycle is even less than 30 days. Aiming at these problems of water injection technique in high temperature, high pressure and low permeability reservoir, the thesis builds up mechanics model of water injection string initially. Under the circumstances of piston effect, ballooning effect, helical buckling effect, temperature effect and friction effect during water injection, this paper deduces calculation formula of string deformation value in different working status (setting, water injection, flushing and so on) and different matching tools. Based on the calculation formula, little calculation software of water injection string deformation is compiled to emulationally calculate string deformation of block fan18-3. By deformation data which is calculated, the paper analyses main influencing factors of water infection string deformation and concrete reason of present water injection string disabled in the block. Based on geology of block fan18-3 and string deformation value which is emulationally calculated, layered water injection string is designed, and matching tools are also designed and improved. In lab, the performance of a set of water injection string and matching tools is evaluated. Finally, the thesis designs a set of layered water injection string which adapts high temperature, high pressure and low permeability reservoir of block fan18-3.