Verkhnechonskoe oil field is situated in Eastern Siberia, Russia. This field is quite unique due to low formation temperatures –the bottom hole static temperature does not exceed 13 degC. This low temperature environment together with low formation fracture gradient present unique challenges for cementing operation. Conventional lightweight system extended by sodium silicate does not meet client well acceptance criteria – no sustained casing pressure (SCP) and successful annular space pressure test due to delayed compressive strength development and relatively high permeability of set cement stone. Failure to meet those criteria’s result in remedial cementing operations and delay of putting wells in production. To overcome this challenge new lightweight cement system based on optimized particles size distribution is successfully introduced for primary cementing of production casing on Verkhnechonskoe field. Implementation of the novel lightweight cement system with high solid volume fraction has allowed client to overcome highlighted issues. Rapid compressive strength development also helped in reduction of well construction time due to shorter wait-on-cement period.
This paper outlines an approach based on the usage of optimized particles size distribution lightweight cement system in low temperature environment included three steps of cementing operation: design of cement system, implementation and evaluation results.