New technology of formation protection for new well into production, and older well workovers
Technical roadmap: Many high productivity mining areas shows formation pressure drop caused by insufficient water and intensified mining activities. The reservoir was seriously polluted by the leakage of well-flushing fluid, seriously reducing the ability of the well to restore its production capacity. This situation is particularly common in the marine oil field. The technology can effectively provent the leakage of fluid into the well during its production or workover, to achieve the optimum protection for the reservoir.
Technologyl implementation: above objects can be achieved by configuring anti-leakage flushing. Detailed formulation is to mix add YBWD-III-type borehole stabilizer to filtered seawater or freshwater, formulating into a solution with 10% concentration. This solution ensures no leakage from flushing fluid during well clean-out and snubbing service operations
The core technology: YBWD-Ⅲ solution can be concentrated to form an active ultra-low permeability micelle membrane on the shallow surface of the formation which is gradually closuring through a unique mechanism of interfacial chemistry. The formation of micelle effectively prevents flushing fluid leaking deeply into the pay zone, achieving no filtration and effectively protecting the production layers.
1, the solution forms a good sealing membrane on the shallow surface in the well with a compressive strength of 4Mpa and above, to ensure the fluid gets into the well without leaking during the construction.
2, the liquid is suitable for the wells using sand controlled technology for production. It can pass through multilayer of sand network with 150 micron pore size filter, while not effect on the application of fluid.
3, when the drilling is completed, the blocking membrane under reverse pressure can be unplugged successfully on their own. The unplugging pressure is 1.0Mpa or less, and no other chemical methods involved.
4, Blocking can be effectively achieved with simple formula leaving no burden for reservoir protection. 5, the material of the fluid is inert, non-toxic, non-volatile, non-flammable, the site preparation is feasible and easy to operate
Application temperature: oil temperature of the pay zone should not be greater than 100 degrees Celsius.
Application result: the technology currently has a wide application in any wells where the pressure is low, and when flushing fluid or killing fluid leakage problem is presented in the production or workover construction. The technology can be used to solve the reservoir pollution caused by liquid leakage, especially common for applying in the high-capacity areas.