Methods and Systems For Determining Near-Wellbore Characteristics and Reservoir Properties

A method comprising:

• a) obtaining non-transient wellbore pressures and production rates along a producing interval of a well;
• b) selecting an inflow equation to describe a relationship between the pressures and production rates in the producing interval, wherein the inflow equation relates at least wellbore pressure, production rate, a reservoir property, and a near-wellbore/completion characteristic;
• c) accessing a model that relates the reservoir property and the near-wellbore/completion characteristic;
• d) utilizing the model with a selected reservoir property value to generate a corresponding near-wellbore/completion characteristic value;
• e) using the inflow equation, the selected reservoir property value, the corresponding near-wellbore/completion characteristic value, and the obtained pressures and rates to determine whether the selected reservoir property value and the corresponding near-wellbore/completion characteristic value at least substantially satisfy the inflow equation;
• f) repeating steps (d) and (e) with a distinct reservoir property value until the inflow equation is at least substantially satisfied establishing a validated reservoir property value and a corresponding validated near-wellbore/completion characteristic value;
• and
• g) reporting the validated reservoir property value and the corresponding validated near-wellbore/completion characteristic value for use in business decisions regarding one or more wells.

A method comprising:

• a) obtaining production log data including wellbore pressures and production rates at one or more specific point(s) in time along a producing interval of a well for at least one flowing rate and for a shut-in condition;
• b) selecting an inflow equation to describe a functional relationship between the pressures and production rates in the producing interval, wherein the inflow equation relates at least wellbore pressures, production rates, reservoir permeability, and skin factor;
• c) accessing a model that relates the reservoir permeability and the skin factor;
• d) utilizing the model with a selected permeability value to generate a corresponding modeled skin factor;
• e) testing the selected permeability value and the corresponding modeled skin factor against the obtained pressures and rates using the inflow equation;
• f) repeating steps (d) and (e) with a distinct selected permeability value until the inflow equation is at least substantially satisfied with a selected permeability value and a corresponding skin factor establishing a validated permeability value and a validated modeled skin factor;
• g) reporting the validated permeability value and the validated modeled skin factor for use in business decisions regarding one or more wells;
• and
• h) producing hydrocarbons from the one or more wells.

A system for isolating reservoir properties from near-wellbore/completion characteristics, the system comprising:

• a processor;
• a memory coupled to the processor;
• an application accessible by the processor, wherein the application is configured to:
• a) obtain a functional relationship between reservoir permeability, skin factor, and at least one measurable characteristic of a well;
• b) receive measured data related to the at least one measurable characteristic;
• c) access a model relating reservoir permeability and skin factor;
• d) utilize the model with a selected permeability value to generate a corresponding skin factor;
• e) utilize the functional relationship and the measured data to test the validity of the selected permeability value and the corresponding skin factor in light of the measured data;
• f) generate a validated permeability value and a corresponding validated skin factor by repeating steps (d) and (e) until the functional relationship is at least substantially satisfied with a selected permeability value and a corresponding skin factor;
• and
• g) report the validated permeability value and the corresponding validated skin factor.