Development And Evaluation Of Gas Well Free Solid Kill Fluid

Well killing fluid is a liquid that used to balance the formation pressure in the processof borehole operation. It is one of the significant pollution sources of hydrocarbon reservoir,which can do great harm to fractured oil and gas reservoir. In the gas reservoir of DaqingXushen gas field, the amount of volcano rock reservoirs is nearly89.8%, and the rock istight, low-porosity and low-permeability. Especially, some gas well has a high temperatureof150℃. Bentonite water-based mud is always used as well killing fluid in traditionalborehole operation. However, this system can lead to gas-cut and short duration. Moreover,the invasion of mud bentonite and barite powder particle into gas reservoir will causepermanent damage. Thus, the preparation of a low damage solid free well control fluid isrequired.Through the experimental analysis, the increased agent, filtration reducing agent, antiswelling agent, corrosion inhibitor and salt crystallization inhibitors were chosen to preparethe novel free solid kill fluid system, which has excellent reservoir protection, goodinhibition, and low solid damage. We also experimental evaluated the new system’s damageto volcano rock. It demonstrated that the new free solid kill fluid has the advantages ofadjustable density, solid free, low filtration and good thermal stability. What’s more, itsdamage is small and has very good protective function on the gas.