Determination of location and type of reservoir fluids based on downhole pressure gradient identification

A system comprising:

• a sensor to measure a pressure in a subsurface formation at a number of depths in a wellbore formed in the subsurface formation across a sampling depth range of the subsurface formation to generate a number of pressure-depth measurement pairs;
• a processor;
• and
• a computer-readable medium having instructions stored thereon that are executable by the processor to cause the processor to,
• partition the sampling depth range into a number of fluid depth ranges, wherein each of the number of fluid depth ranges comprises a range where a type of reservoir fluid is present in the subsurface formation;
• and
• determine a fluid gradient for the type of the reservoir fluid for each of the number of fluid depth ranges.

A non-transitory, computer-readable medium having instructions stored thereon that are executable by a processor to perform operations comprising:

• receiving a measurement of a pressure in a subsurface formation at a number of depths in a wellbore formed in the subsurface formation across a sampling depth range of the subsurface formation to generate a number of pressure-depth measurement pairs;
• partitioning the sampling depth range into a number of fluid depth ranges, wherein each of the number of fluid depth ranges comprises a range where a type of reservoir fluid is present in the subsurface formation;
• and
• determining a fluid gradient for the type of the reservoir fluid for each of the number of fluid depth ranges.