Underproduction	Production that is less than allowable assigned to a proration unit.
Unitization	Joint operations to maximize recovery among separate operators within a common reservoir.
Waterflood	Injecting water in one well causing oil not recovered by primary production to migrate to an adjacent well.
Wells	Development Well	A well drilled to a known producing formation in a previously discovered field.
	Exploratory Well	Any well drilled for the purpose of securing geological or geophysical information to be used in the exploration or development of oil, gas, geothermal, or other mineral resources, except coal and uranium, and includes what is commonly referred to in the industry as “slim hole tests,” “core hole test,” or seismic holes”.
Wildcat	A well drilled for the purpose of discovering a new field or reservoir.
Working Interest	Interest(s) in a well which bears the drilling and operating expenses.
Zone	Interval of subsurface formation.