The technology of dumping and cleaning of produced water at a well cluster developed by TatNIPIneft is being successfully implemented at TATNEFT Company for separation and cleaning of the water produced at the well cluster with subsequent water injection into the corresponding wells of the same cluster.

 

Pilot testing of the developed technology was carried out at the installation mounted at GZU well cluster of CDNG-50A-4, Archangelskoye field of NGDU Yamashneft, which is owned by TATNEFT.

 

The main factors of project effectiveness were decrease in the use of fresh water for reservoir pressure maintenance (RPM), and reduction of energy consumption for pumping over fresh water, production of wells and sewage water.

 

The technology of dumping and cleaning of associated produced water at a well cluster allows reducing the volume of fluid pumped through the oil gathering and RPM systems and consumption of fresh water for injection. This engineering development allows decreasing the diameters of oil and water pipelines, which reduces capital costs for their construction. Such an approach “unloads” preliminary water removal installations and oil treatment assemblies, thus eliminating capital costs for their expansion. As a result, the cost of oil treatment can be decreased.

 

Briefly, the process includes the first stage, during which a demulsifier is injected into produced products at the well cluster. Following this, preliminary gas separation takes place in the surge vessels. The wells' production is treated in the oil coalescer unit for the purpose of intensifying of the water droplets enlargement process. The process of settling is carried out in the first section of the sump for breaking into oil and water. Water separated at the coalescing filter is treated in order to intensify the process of remaining oil droplets consolidation. Settling of water for separation of oil droplets takes place in the second section of the sump. Treated water is then injected into the corresponding wells of the same cluster.

 

The results of pilot tests have proven the effectiveness of this technology. This engineering development of TATNEFT was awarded the first degree diploma at the “Resource Efficiency” contest held in Tatarstan.