Methods to estimate downhole drilling vibration indices from surface measurement

A method of estimating severity of downhole vibration for a wellbore drill tool assembly using a computer processor, comprising the steps:

• a. identifying a dataset comprising (i) parameters for a selected drill tool assembly comprising a drill bit, (ii) selected wellbore dimensions, and (iii) selected measured depth (MD);
• b. selecting a reference downhole vibration index for at least one of downhole torque, downhole weight on bit, and downhole bit rotary speed, downhole axial acceleration;
• c. identifying a corresponding selected surface parameter including at least one of surface torque, a surface hook-load, and surface drill string rotation rate, and surface axial acceleration, and calculating a corresponding reference surface vibration attribute for the selected reference downhole vibration index;
• d. determining a surface vibration attribute obtained in a drilling operation, the determined surface vibration attribute corresponding to the identified selected surface parameter (step c);
• and
• e. estimating, using the computer processor, a downhole vibration index by evaluating the determined surface vibration attribute (step d) with respect to the calculated reference surface vibration attribute (step c).

A method of estimating severity of downhole vibration for a drill tool assembly using a computer processor, comprising the steps:

• a. identifying a dataset comprising selected drill tool assembly parameters;
• b. selecting a reference downhole vibration index for the drill tool assembly;
• c. identifying one or more ratios of:
• the selected reference downhole vibration index for the drill tool assembly (step b) to a calculated reference surface vibration attribute;
• d. determining a surface vibration attribute derived from at least one surface measurement or observation obtained in a drilling operation;
• and
• e. estimating, using the computer processor, a downhole vibration index by evaluating the determined surface vibration attribute (step d) with respect to one or more of the identified ratios (step c).

A method of estimating severity of downhole vibration for a wellbore drill tool assembly using a computer processor, comprising the steps:

• a. identifying a dataset comprising selected drill tool assembly parameters;
• b. selecting a reference downhole vibration index for the drill tool assembly;
• c. identifying one or more ratios of:
• the selected reference downhole vibration index for the drill tool assembly (step b) to a rate of change associated with a selected reference surface vibration attribute;
• d. determining a surface vibration attribute derived from at least one surface measurement or observation obtained in a drilling operation, the determined surface vibration attribute corresponding to the selected reference surface vibration attribute;
• and
• e. estimating, using the computer processor, a downhole vibration index by evaluating the determined surface vibration attribute (step d) with respect to one or more of the identified ratios (step c).

A method of estimating severity of downhole vibration for a wellbore drill tool assembly using a computer processor, comprising:

• a. identifying a dataset comprising selected drill tool assembly parameters;
• b. selecting a reference downhole vibration index for the drill tool assembly;
• c. calculating a reference surface vibration attribute for the selected reference downhole vibration index, including calculating one or more characteristic periods of vibration of the drill tool assembly;
• d. determining a surface vibration attribute including a dominant period, derived from at least one surface measurement or observation obtained in a drilling operation;
• and
• e. estimating, using the computer processor, a downhole vibration index by evaluating the relationship between the determined dominant period surface vibration attribute with respect to the calculated one or more characteristic periods.