The application range of oxidized asphalt.

Oxidized asphalt is a product made by heating the asphalt and oxidizing it through the air.

After oxidation , the asphaltene increased and the colloid content decreased.In physical properties are manifested as elevated softening point.

Oxidized asphalt has good water dispersion and it distributed in the liquid phase in the form of asphalt particles. The components of the asphalt drilling fluid treatment agent which based on physical actionare mainly , those water insoluble substances are moderately dispersed in the drilling fluid without agglomeration and floating phenomenon,play the role to improve the application of drilling fluid.Due to the good plugging performance of the insoluble bituminous particles, it can be arbitrarily embedded in the formation micro-cracks to prevent shale collapse, and when it combined with the plugging agent, bituminous particles will play cementing role, which can improve the plugging effect.

Different oxidized asphalt products (150~220℃) can be prepared with different raw materials and through the control of oxidation degree.Oxidized asphal's functions are closely related to the nature of oxidation asphalt and softening point or oxidation degree, we should pay attention to the choice when using.

Oxidized asphalt does not increase the viscosity, and even can slightly reduce viscosity and water loss effect.It has certain surface active agent, it can improve the drilling fluid filtration control ability, prevent spalling shale collapse, reduce friction resistance, inhibit hydration dispersion, improve the recovery of cuttings, protect the stability of drilling fluid colloid and improve rheology.And it's no fluoresce,so it will not affect the fluorescence analysis of the sand sample.

The advantages of using oxidized asphaltas below:

Oxidized asphalt can be used in vertical Wells, deep Wells, deviated Wells, horizontal Wells,also can bue used in fresh water drilling fluid, brine water drilling fluid and sea water drilling fluid.

Because Oxidized asphalt is powdery, it can be used in both summer and winter without agglomeration, and the construction is extremely convenient.

Oxidized asphalt can resist temperature above 150℃, whether shallow well or deep well can be used.

Oxidized asphalt is processed by pure asphalt. It can be highly dispersed in drilling fluid, with some deep solutions and most insoluble substances.It can be filled into the micro-cracks of borehole wall arbitrarily, which can effectively prevent the use of spalling and collapsing Wells.

Oxidized asphalt contains some cations, and the solution is positively charged, which is conducive to inhibiting the hydration and dispersion of mud shale, so it can further prevent collapse.

Oxidized asphalt can effectively reduce friction and blockage due to some surfactants inside.

Oxidized asphalt can using the mixing funnel directly into the mud, do not need to be mixed into water solution to join.

General low softening point asphalt completely softened into a liquid when the temperature is high, lose the blocking effect, and immediately clustered together when the temperature is low, adhere to the vibrating screen cloth, block the sieve hole, lead to drilling fluid difficult to sift out. However,oxidized asphalt has high softening point , it completely overcome the above.