Abstract: The present invention refers to a mandrel assembly for chemical injection in use in an oil well production string where the water depth can reach 3,000 m, exerting extreme hydrostatic pressures on the mandrel. The mandrel assembly is capable of dosing the chemical fluid flow rate to avoid some types of unwanted situations in the production string, mainly related to fouling. It has the characteristic of not using injection valves having small diameters, causing the annular space between the mandrel body and the inner part to ensure greater space for the flow of chemical fluid, thus reducing the likelihood of a possible plugging. Such characteristics ensure lower maintenance interventions, thus generating lower costs and increasing well reliability.

Abstract: The present invention addresses to a method of removing scale from the DHSV of the oil production string aiming at maintaining the production of the wells and thus avoiding the loss of production. First, a neutralizing solution is placed in the service line, before pumping the scale removing solution through the string to act on the DHSV. Next, the acid is pumped into the production string to react with the calcium carbonate scale. After the time for the dissolution of the scale inside the DHSV, the well is opened for production by the service line. The spent acid is mixed with the neutralizing solution inside the service line, reducing its corrosiveness in relation to the service line, contributing to its preservation.

Abstract: The invention is related to a joint application process of two treatments, scale removal and inhibitor squeeze injection. Through the simultaneous positioning inside the reservoir, it can be applied in scale removal operations for carbonate formations, such as the pre-salt case. Accordingly, there is a way to improve the efficiency of reservoir management, through an innovation in the scaling management process.

Abstract: The present invention refers to a mandrel assembly for chemical injection in use in an oil well production string where the water depth can reach 3,000 m, exerting extreme hydrostatic pressures on the mandrel. The mandrel assembly is capable of dosing the chemical fluid flow rate to avoid some types of unwanted situations in the production string, mainly related to fouling. It has the characteristic of not using injection valves having small diameters, causing the annular space between the mandrel body and the inner part to ensure greater space for the flow of chemical fluid, thus reducing the likelihood of a possible plugging. Such characteristics ensure lower maintenance interventions, thus generating lower costs and increasing well reliability.