Abstract

The properties of the filter cake through maximum reservoir contact (MRC) and extended reach (ER) wells are not constant due to the presence of the drilled-cutting. The formation cuttings contamination in the drilling fluid during the drilling operation influences the drilling fluid properties as well as the filter cake properties.

This study focuses on assessing the effect of the sandstone formation drilled-cuttings on the filter cake sealing properties and the internal solid invasion depth in horizontal section. Three different drilling fluid samples were collected at different points of a horizontal section during drilling operation. The drilling fluid samples were collected at the flow line coming from the well after shale shaker. High pressure high temperature (HPHT) fluid loss test was conducted to form the filter cake on top of 0.25 inch ceramic disc (35 micron). The composition of filter cake was evaluated using SEM and XRD. CT scan technique was used to evaluate the internal solids invasion of the different drilling fluid samples.

The results from this study showed that the internal invasion is directly affected by the changes of sand contents in the filter cake. The internal drilling fluid solids invasion depth reached 3-4 mm when the sand content was lower than 25 wt % of the filter cake solids. Increasing the sand content more than 30 wt % in the filter cake solids allowed the drilling fluid to invade up to more than 6 mm with high concentration due to the degradation in the cake permeability.

The result of this work will be useful to investigate diversion process to remove the formation damage from maximum reservoir contact and extended reach wells in sandstone reservoirs.

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