A Study Of Treatment Agent Wettability Mechanism Of Oil Based Drilling Fluid

Petroleum is an important resource and high grade fuel,drilling fluids is closely related to drilling engineering.Water-in-oil drilling fluids is a fluids with strong inhibition to stabilize the borehole wall and inhibit the shale,especially suitable for complex water sensitive formation conditions,has good lubricity,extremely salt-resistant and cuttings-resistant.This characteristics of the drilling mud can be recycled and in-site maintenance is simple,and now it has become an important means of drilling high temperature deep wells,highly deviated directional wells, horizontal wells, a variety of trouble wells and reservoir protection.Now,the oil-based drilling fluids used more and more widely, and the problem of treatment agent on reservoir wettability of oil-based drilling fluid system has been unclear understanding, which is unfavorable for the application of oil-based drilling fluids while a unclear understanding of protection of the reservoir. It is necessary to develop oil-based drilling fluid reservoir wettability evaluation. Although research in this area is still in the research stage indoors, and it is can not be put on-site applications temporarily, but in the long term, a in-depth study to further improve the protection of reservoirs for enhanced oil production technology is significant. Therefore, this paper is to deepen the understanding of mechanism of oil-based drilling fluid on reservoir wettability through the macroscopic experimental research and microstructure characterization of the treatment agent,and strive to find some new oil-based drilling fluid for wettability evaluation methods,which is helpful for the protection of reservoir during the site of drilling.This article discusses the current oil-based drilling fluids used composition and characteristics, and describes the wettability of reservoir rock, as well as research status around the world, Focuses on the mechanism of reservoir wettability treatment agent used in oil-based drilling fluid,such as base oil, primary emulsifier and auxiliary emulsifier, wetting agent, organic soil, oxidized asphalt, consider lowering loss agents, weighting agents, inorganic ions, and the temperature. Contact angles were determined using a single component and mud filtrate system on the simulated sandstone, carbonate and oil-wet reservoir wetting contact angle analysis of the various components and systems of reservoir wettability law. By measuring the different layers of reservoir rock by oil-base mud invading dirt around the permeability recovery and the contact angle changes, the system evaluation the changes of reservoir wettability and formation damage of the individual components as well as oil-based mud system, and finally gives a number of new measures for the protection of reservoirs.