A nano-particle based approach to improve filtration control of water based muds under high pressure high temperature conditions

There have been many attempts to improve the filtration control of water based muds under High Pressure High Temperature(HPHT)condition using a cost effective approach.Nano particles are perhaps the best option considering their successful applications reported in many studies.However,they are often expensive and pose unfavourably changes on the rheology of the muds.In this paper,an attempt was made to show the application of Nano Glass Flakes(NGFs)as a cheap but effective nano particle to control the filtration of water based muds under HPHT conditions.Performing a series of rheology,filtration and conductivity tests on the mud samples with unmodified NGFs revealed that this nano particle increases the mud rheology,yield point and gel strength of the mud with a slight impact on the filtration loss.However,by modifying the surface charges of NGFs with a cationic surfactant,filtration loss was significantly reduced without any severe impacts on the mud rheology.Considering the conductivity of the mud which increases by adding the modified NGF,this nano particle might be a good choice to improve the overall performance of water based muds under HPHT conditions.

An approach to improve wellbore stability in active shale formations using nanomaterials

Drilling through active shale formations has been a challenging practice in the oil and gas industry for a long period of time,given the complexity of shale structure and its interaction with Water Based Muds(WBMs).Although there have been many additives and methodologies proposed for a safe drilling through shale formations using WBMs,little success has been reported to the application of these methods once tested under different field conditions.In this paper,a new WBM formulated by nanomaterials was proposed to stabilize active shale layers during drilling.A series of rheological,density,filtration loss,bentonite dispersion and shale recovery tests were conducted on the mud samples formulated by nanosilica and Nano Glass Flakes(NGFs).The results indicated that NGF,as a cheap but effective nanomaterial,is able to significantly reduce the flirtation loss without posing any significant impacts on the density and the rheology of WBMs.It also appeared that the bentonite molecules were incapable to either hydrate or disperse in the drilling fluid system in the presence of NGFs.It seems that NGFs can stabilize clay minerals and reduce the filtration loss as remarkably efficient additive,but caution must be taken to ensure that they are properly disperse in the WBMs.