Fluid systems & Rheology – Anthony Nwachukwu
Completions and workover fluids system & rheology are basically fluid designed to be used during completions and workover well operations. The fluids are prepared to specification based on the reservoir information or well data as the case may be.
TECHDaer Services Ltd. refined the engineering of completion fluids and technologies that accelerate and maximize reservoir production with minimal Health,Safety &Environment impact. Our fluids system also provides a seamless and cost effective solution for optimizing productivity throughout the completions or workover operations.
Completions and work over fluids are fluids used from the Well Bore Clean out operation through the mounting of Xmas tree on
the well. They involve the WBCO chemicals (Hivis/sweep pills & surfactant), fluid loss control chemicals or LCM (Calcium carbonate), packer fluid and also the basic completions or workover fluid –Brine.
WHY ARE THEY USED?
The invention of fluids and its techniques is to optimize / enhance the production of hydrocarbons from subterranean formations and also control reservoir behavior while carrying out workover or completions operations.Completion and workover fluids is important in the improving the commercialization of a producing formation as they play a major role in preventing permeability damage and controlling formation pressure during completions or workover operations.
In particular, fluids and technique are disclosed and claimed which remove wellbore damage and near wellbore damage in the form of coating formed from drilling and production related operation i.efiltercakes.
Several decades ago, engineers realized that the use of drilling fluids during completions was inappropriate because fluids caused severe damage of the production zone.
An important fact to keep in mind with completion and workover fluids is that, unlike drilling fluids, they do not contain drill solids. This means that there is no effective bridging material available to reduce fluid leakoff.
FLUIDS SYSTEM PREPARATION AND DESIGN
Selection of completions /workover fluids system is entirely dependent upon its function, which in turn depends on the completions method. The method may involve undereaming, gravel packing, perforating or workover. Completions fluid used for undereaming have to display formation bridging, low spurt loss and filtrate lossto support the sand and prevent sloughing.
For gravel pack, because the filter cake will be trapped between the gravel pack and the formation, the fluid should be composed of particles soluble in acid or oil and small enough not to bridge off the gravel pack when the well is flowed.
Also during the Well Bore Clean Out operation, the sweep pills would be designed in such a way that the pill is powerful enough to lift debris or particles down hole out to surface with a desired pump rate and to also overcome debris or particles gravitation in well bore.