US 12,123,863 B2
Processes and systems for determining if downhole fluids are in equilibrium or non-equilibrium
Melanie Jensen, Cambridge, MA (US); Lalitha Venkataramanan, Lexington, MA (US); Sandip Bose, Chestnut Hill, MA (US); Peter Tilke, Watertown, MA (US); Oliver C. Mullins, Houston, TX (US); Li Chen, Beijing (CN); and Denise E. Freed, Newton Highlands, MA (US)
Assigned to Schlumberger Technology Corporation, Sugar Land, TX (US)
Appl. No. 18/043,616
Filed by Schlumberger Technology Corporation, Sugar Land, TX (US)
PCT Filed Sep. 2, 2021, PCT No. PCT/US2021/071354
§ 371(c)(1), (2) Date Mar. 1, 2023,
PCT Pub. No. WO2022/051764, PCT Pub. Date Mar. 10, 2022.
Claims priority of provisional application 63/073,788, filed on Sep. 2, 2020.
Prior Publication US 2023/0349881 A1, Nov. 2, 2023
Int. Cl. G01N 33/28 (2006.01); E21B 49/08 (2006.01)
CPC G01N 33/2823 (2013.01) [E21B 49/081 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A process for determining asphaltene equilibrium between two or more downhole geographic locations comprising:
measuring one or more fluid properties of a plurality of fluid samples at varying downhole depths to generate a one or more downhole fluid analysis measurement data points;
selecting an asphaltene diameter distribution based on prior knowledge;
utilizing the asphaltene diameter distribution to fit a set of one or more equation of state curves to the one or more downhole fluid analysis measurement data points to define a model of fitted equation of state curves and to determine one or more posterior distributions of asphaltene diameters, wherein a plurality of models of fitted equation of state curves is obtained by fitting a plurality of sets of one or more equations of state curves and determine model dependent posterior distributions of asphaltene diameters; and
determining if the varying downhole depths are in an asphaltene equilibrium by determining whether the one or more posterior distributions of asphaltene diameters is consistent with that of asphaltenes in equilibrium.