Providing selective dissolvable coatings on a multi-shell core system for inflow control devices

A method of forming a multishell core composite, the method comprising:

• coating by a ball mill, a core with a thin layer of a binder;
• coating by a ball mill, a first layer on the core comprising the binder, the first layer comprising a first metal oxide nanoparticle, the first layer is dissolvable in contact with a aqueous fluid;
• coating by a ball mill, a second layer on top of the first layer, the second layer comprising a second metal oxide nanoparticle, the second layer is dissolvable in contact with a aqueous fluid;
• and
• coating by a ball mill, a third layer on top of the second layer, the third layer comprising a third metal oxide nanoparticle, the third layer is dissolvable in contact with a hydrophobic fluid.

A inflow control device (ICD) of a production well comprising:

• a plurality of inflow ports through which a reservoir fluid flows into the ICD;
• a multi-shell core composite placed in the ICD, the multi-shell core composite comprising:
• a core;
• a first layer, comprising a mixture of a binder and a first metal oxide, which is dissolvable in contact with a aqueous fluid, the first layer coated on the core;
• a second layer, comprising a second metal oxide, which is dissolvable in contact with a aqueous fluid, the second layer coated on the first layer;
• and
• a third layer, comprising a third metal oxide, which is dissolvable in contact with a hydrophobic fluid, the third layer coated on the second layer;
• and
• an outflow port through which the reservoir fluid flows out of the ICD into the production well.