Analysis Of Oil Used In Oil Based Drilling Fluid System And Research On The Mechanism Of Organic Modified Materials Used In Oil Based Drilling Fluid

As the developing of the oilfield development technique,the emergence of deep water drilling and directional well and in order to create an energy conservation and environment protection society,people paid more and more attention on oil based drilling fluid.Oil based drilling fluid,which has excellent lubricating property,shale inhibition and thermal endurance,could efficiently protect formation,recycling use and save more energy.The oil based drilling fluid consist of oil,water,organic clay and functional additions.The oil based drilling fluid consist of oil,water,organic clay and functional additives.This passage included three main parts which all about oil based drilling fluid.First part is the analysis of paraffin oil and gas to liquid by using comprehensive GCxGC system and GCMS.The oil has significant effect on the property of the drilling fluid as the continuous phase.Especially for the deep water drilling,which has a wide range of processing temperature.The isoparaffin could avoid the sharp increase in viscosity by reduce intermolecular interaction.The result shows that the gas to liquid is mainly consist of n-alkanes and isoparaffin.The paraffin oil is much more complicated which consist of n-alkanes,isoparaffin,olefin and aromatic hydrocarbon.Second part is the analysis of organic clay's composition and structure,including the compare of commercial organic clay and organic clay prepared in lab.And also we do research on the effect organic clay brings to drilling fluid at high temperature.The result shows that adsorption and desorption of modifier in organic clay's interlayer will take place at high temperature.For the commercial organic clay,much more free modifier will come into the interlayer and then the arrangement of modifier will take place.This will lead to the improvement of organic clay's modification degree and increase the viscosity of the drilling fluid finally.Third part is the exploitation of the thinner.We modified polyhydroxyphenol which derived from plants with reactive amine to get a low cost and high performance thinner.We also represented its structure by IR,NMR and MS.After that,we put those into oil based drilling fluid to evaluate the performance.When the drilling fluid has proper apparent viscosity and plastic viscosity,this kind of thinner could prevent it from sharp increasing in viscosity at high temperature.When the drilling fluid has high apparent viscosity and plastic viscosity,this kind of thinner could reduce the viscosity efficiently.The reduce of viscosity is higher than 30%calculated by apparent viscosity.Besides,this kind of thinner has a good performance in reducing fluid loss.Therefore it could be used as fluid loss additive as well.