Workflow for pore pressure and permeability estimation in unconventional formations

A pore pressure and permeability analysis system to facilitate a field operation of an unconventional reservoir, comprising:

• a computer processor;
• and
• memory storing instructions, when executed by the computer processor comprising functionality for:
• performing a diagnostic fracture injection test (DFIT) of a formation zone in the unconventional reservoir to generate a DFIT dataset, wherein each entry of the DFIT dataset comprises a decline pressure and a time interval that are measured prior to any radial flow regime occurs in the formation zone during the DFIT,
• wherein the formation zone is one of a plurality of formation zones in the unconventional reservoir;
• selecting, from a collection of the time interval of each entry of the DFIT dataset, a plurality of time intervals;
• analyzing the DFIT dataset at the plurality of time intervals to generate tabulated entries of estimated permeability versus estimated pressure;
• determining, prior to said any radial flow regime occurs in the formation zone during the DFIT, a true reservoir permeability in the formation zone by extrapolating the tabulated entries of estimated permeability versus estimated pressure;
• generating, according to the true reservoir permeability in each of the plurality of formation zones, a ranking of the plurality of formation zones;
• selecting, from the plurality of formation zones and based on the ranking, a target formation zone having the true reservoir permeability meeting a pre-determined criterion;
• and
• performing, based at least on the true reservoir permeability of the target formation zone, the field operation of the unconventional reservoir,
• wherein the field operation comprises a hydraulic fracturing operation or an enhanced oil recovery process.

A system comprising:

• a well control system for performing a field operation of an unconventional reservoir;
• and
• a pore pressure and permeability analysis system comprising a computer processor and memory storing instructions, when executed by the computer processor comprising functionality for:
• performing a diagnostic fracture injection test (DFIT) of a formation zone in the unconventional reservoir to generate a DFIT dataset, wherein each entry of the DFIT dataset comprises a decline pressure and a time interval that are measured prior to any radial flow regime occurs in the formation zone during the DFIT,
• wherein the formation zone is one of a plurality of formation zones in the unconventional reservoir;
• selecting, from a collection of the time interval of each entry of the DFIT dataset, a plurality of time intervals;
• analyzing the DFIT dataset at the plurality of time intervals to generate tabulated entries of estimated permeability versus estimated pressure;
• determining, prior to said any radial flow regime occurs in the formation zone during the DFIT, a true reservoir permeability in the formation zone by extrapolating the tabulated entries of estimated permeability versus estimated pressure;
• generating, according to the true reservoir permeability in each of the plurality of formation zones, a ranking of the plurality of formation zones;
• selecting, from the plurality of formation zones and based on the ranking, a target formation zone having the true reservoir permeability meeting a pre-determined criterion;
• and
• performing, based at least on the true reservoir permeability of the target formation zone, the field operation of the unconventional reservoir,
• wherein the field operation comprises a hydraulic fracturing operation or an enhanced oil recovery process.