Abstract
Sand production in oil and gas wells is badly affecting production rates, damaging downhole and surface equipment. Knowledge of source of sand production and its amount can prolong well life by performing timely remedial operations. Nowadays, companies rely on stress analysis and numerical models to predict source of sand production in wells producing from several layers commingled and at the same time amount of sand production is measured on surface with separators.
On the other side, wireline sand detection tool allows to quantify and locate source of sand production downhole as well produces, and when run in combination with production logging tool string, to quantify multiphase inflow profile into the well simultaneously.
Most of the wells on Dzheitune (LAM) field, located offshore Caspian Sea, were completed with dual tubing at the beginning of field development. Over the time, depletion in reservoir pressure caused formation failure in A-sand reservoir and wells producing from this formation started to produce sand. Some wells had to be recompleted by pulling out of hole dual string completion and running in hole single tubing with sand screens across existing perforations. Before pulling dual tubing, some wells were logged with slim sonic tool to locate top of sand accumulation in casing to long tubing annulus. This information was used to determine depth for tubing cut, before pulling it out of hole; whenever such operation was required. Most of the newly drilled wells are completed with single tubing having sand screens.
Field examples, presented in this paper, describe principles of data acquisition with sand detection tool when run in combination with production logging string, and results of logging in slightly deviated wells completed with sand screens. Comparison of multi-phase inflow profiles with source of sand production showed that most of sand is being produced through hotspot in sand screens; i.e. eroded hole that was generally located across topmost section of the screens in almost all the wells that were logged. Logging results are then used for planning remedial operations to pull tubing out of hole and to replace damaged screens.
