The Laboratory Evaluation Experiment On The Reservoir Damaged By Drilling Fluid

The laboratory reservoir damage evaluation is a statistical experiment. In order to make acomprehensive and accurate judgement, there must be massive experiments. At the same timeit is also a simulation experiment, the experimental conditions and discriminant rule willproduce conclusive effect on the final conclusion of the experiment.This paper analyzes the damage degree of oil well stratum in each link of thedevelopment or production, then carrys out all aspects of optimization, avoiding or restoringthe productivity of oil well largely. This paper studies the pollution degree and depth ofdifferent drilling fluid on the stratum. it studys the pollution law of drilling fluid under certainpressure and temperature using “core segment permeability test method”. And it studys themechanism of pollution using the core slices, chemical composition and particle size analysis.The results show that: there is a consistency between the natural cores’ pollution law andartificial cores’ pollution law. The permeability and the contamination rate of differentpermeability reservoirs are different. Based on the analysis of slice, the analysis aluminumcharacter of clay and the analysis of filter size, it shows that the stratum pollution in theprocess of drilling is mainly due to the solid particles and treatment agent particles. Based onthe evaluation, it could provide security for the exploitation of petroleum.