<simpleType name="WellType">
    <restriction base="NMTOKEN">
        <enumeration value="Oil" />
        <enumeration value="Gas" />
        <enumeration value="IndustrialDisposal" />
        <enumeration value="Thermal" />
        <enumeration value="Storage" />
        <enumeration value="Water" />
        <enumeration value="Injection" />
        <enumeration value="Uranium" />
        <enumeration value="Relief" />
        <enumeration value="NonWell" />
        <enumeration value="DisposalWell" />
        <enumeration value="Sulfur" />
        <enumeration value="HorizontalOil" />
        <enumeration value="HorizontalGas" />
        <enumeration value="Brine" />
        <enumeration value="DirectionalOil" />
        <enumeration value="DirectionalGas" />
        <enumeration value="DirectionalNonWell" />
        <enumeration value="Environmental" />
        <enumeration value="IndustrialNonWell" />
        <enumeration value="Other" />
    </restriction>
</simpleType>

• WellType
• pidx:WellType