The inhibitor squeezing into the reservoir of the Verkhnechonskoe field prevents from the gypsum scale precipitation of the associated salt waters

The article describes the first experience of protecting horizontal wells from gypsum scaling, using the inhibitor squeezing technology. Various mechanisms of the inhibition of gypsum deposits by phosphonate inhibitors are determined.
Materials and methods
Inhibitors, intended for protecting wells from gypsum sediments, were selected, according to the definite adsorptive and stripping properties.
Results
The procedures of the inhibitor squeezing into the reservoir of horizontal wells were highly productive. Pre-designed performance targets, concerned withthe protection time, were achieved and exceeded.
1. As the results of the experience, it was discovered, that the inhibitor squeezing technology of scaling into the producing well prevents from the gypsum scale precipitation in the bottom-hole area and in the pumping equipment.
2. The application of the technology leads to the increasing of the well overhaul period, cost saving for sediment preventing and removing in comparison with the base case. The precipitating protection mechanism of wells gives substantive results during the squeezing into the bottom-hole area: prolong inhibiting compared with two-site sorption.
Сonclusions
1. Before inhibitor squeezing, it is recommendedto carry out the procedure of the bottom-hole treatment with the aqueous caustic soda in order to remove the existing gypsum sediments in the bottom-hole area to achieve the better inhibitor adsorption on the formation.
2. Selecting reagents for future squeezing, it is recommended to choose multicomponent commodity forms of inhibitors. They contain different components (alcohols, surfactants, etc.) in addition to the active base, that promote the better reagent sorption on the formation.