chemical preparations, products, and compositions, namely, ethylene derived ester based fluid in the nature of continuous phase and calcium chloride, sodium chloride brine, and inorganic salt solutions as the internal phase of an invert emulsion, organophyllic clay viscosifier surface active organics, and weight material, all for use in oil fields, gas fields, oil production or gas production; chemical preparations, products, and compositions, all for use in drilling, completion and workover of oil and gas wells, namely, drilling, drill-in and completion fluids; chemical additives for use in drilling, completion and workover of oil and gas wells; completion fluid chemicals, drilling muds, drilling fluid additives and chemical viscosifiers, all for use in drilling, completion and workover of oil and gas wells