Manufacture of water wet artificial core by chemical modification method

摘要

A limited number of reservoir rocks can be drilled for laboratory experiments,so artificial core is often used to study the multiphase flow and EOR mechanism during physical simulation experiments. Artificial core manufacturing method includes epoxy cementing and high temperature sintering processes. Conventional epoxy resin cement core used was commonly oil wet. By adopting the method of high temperature sintering or surfactant cementation,the wettability requirements of reservoir rocks can be satisfied;however,it may have water sensitivity and unstable hydrophilicity issues. The traditional process of epoxy cement is improved on the basis of above mentioned facts. In this paper the method of manufacturing water wet artificial core was improved and simplified by chemical modification. The non-ionic hydrophilic group for epoxy molecule is added by the chemical reaction of E-51(epoxy)and glycine,and then the chemically modified epoxy and curing agent can cement quartz sands directly. The mixture of chemically modified epoxy resin and curing agent before solidification can be diluted by water directly instead of acetone which is toxic for human body. The test of contact angle shows that cured epoxy resin and cemented core slice are both water wet. Strength,porosity and permeability of cementing core are essentially the same with the conventional cementing one;moreover,the pore distributions by NMR test are the same. Furthermore,the water sensitivity phenomenon does not exist,and its’properties(strength,porosity and permeability)basically remain unchanged after soaking by kerosene or water for 48 hours. This kind of water wet core manufacturing method is simple since the process doesn’t need high temperature curing and it’s more suitable to study the fluid flow in porous media and EOR method in light of the stable property.