Definition - What does Well Stimulation mean?
Well Stimulation is the process of cleaning the available flow channels or creating new flow channels with in the rock formation to improve permeability. The main purpose of Well Stimulation is to improve the flow hydrocarbons into the wellbore so as to increase the productivity. Well Stimulation operations can be carried out in existing as well as newly drilled wells.
Petropedia explains Well Stimulation
While drilling an oil well, oil well operations like circulation of drilling fluids, pumping of cement slurry, perforation and pumping of fluids into the wellbore through the surface equipment are carried out. The suspended particles that are present in these fluids interact with the materials that are originally present in the reservoir. High temperature and pressure modifies the permeability of the formation or sometimes plugs the formation itself.
This phenomenon is referred to as formation damage or skin effects. In simple terms, any operation carried out on a well that can lead to formation damage to some extent and reduce the productivity of the well. Well Stimulation techniques are designed to increase permeability of formation. This is achieved by two ways, i.e., matrix acidization and reservoir fracturing.
Matrix acidization involves pumping calculated quantity of acid into the wellbore at certain pressure without fracturing the formation which dissolves the foreign material thus improves the permeability. Hydrofluoric acid is used for sandstone while hydrochloric acid is used for limestone.
Hydraulic fracturing involves pumping of fluids (proppant, water acid, corrosion inhibitors, etc.) into the wellbore at higher pressure that causes the reservoir to from cracks. This creates higher permeability thus allows the hydrocarbons to flow.