# US 11,994,020 B2 · Mapping inter-well porosity using tracers with different transport properties > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,994,020 B2 - Document ID: US11994020B2 - Status: Granted - Kind: B2 - Application number: 17/933,910 - Filed: 2022-09-21 - Published: 2024-03-21 - Granted: 2024-05-28 - Earliest claimed: 2022-09-21 - Assignees: Saudi Arabian Oil Company - Applicants: Aramco Services Company - Inventors: Hsieh Chen; Martin E. Poitzsch; Hooisweng Ow - Web page: https://patentgrep.com/patent/US11994020B2 ## CPC - E21B 47/11: using tracers; using radioactivity - E21B 49/008: {by injection test; by analysing pressure variations in an injection or production test, e.g. for estimating the skin factor (measuring pressure E21B47/06)} - E21B 2200/20: Computer models or simulations, e.g. for reservoirs under production, drill bits - E21B 2200/22: Fuzzy logic, artificial intelligence, neural networks or the like - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract A method for mapping inter-well porosity includes injecting a Type 1 tracer into a hydrocarbon-bearing reservoir via an injector well, wherein the Type 1 tracer is a passive tracer, injecting a Type 2 tracer into the hydrocarbon-bearing reservoir via the injector well, wherein the Type 2 tracer is a porosity-sensitive tracer, detecting a breakthrough of the Type 1 tracer and a breakthrough of the Type 2 tracer in produced fluid at a producer well, and comparing the breakthrough of the Type 1 tracer with the breakthrough of the Type 2 tracer to provide a map of inter-well porosity. ## Claims ### Claim 1 A method for mapping inter-well porosity comprising: injecting a Type 1 tracer into a hydrocarbon-bearing reservoir via an injector well, wherein the Type 1 tracer is a passive tracer; injecting a Type 2 tracer into the hydrocarbon-bearing reservoir via the injector well, wherein the Type 2 tracer is a porosity-sensitive tracer; detecting a breakthrough of the Type 1 tracer and a breakthrough of the Type 2 tracer in produced fluid at a producer well; and comparing the breakthrough of the Type 1 tracer with the breakthrough of the Type 2 tracer to provide a map of inter-well porosity. ### Claim 2 (depends on 1) The method of claim 1, wherein the Type 1 tracer is selected from the group consisting of dipicolinic acid (DPA), 4,7-bis(sulfonatophenyl)-1,10-phenanthroline-2,9-dicarboxylic acid (BSPPDA), 2-fluorobenzoic acid, 3-fluorobenzoic acid, 4-fluorobenzoic acid, 2,3-difluorobenzoic acid, 2,4-difluorobenzoic acid, 2,5-difluorobenzoic acid, 3,4-difluorobenzoic acid, sodium thiocyanate (NaSCN), sodium bromide (NaBr), and combinations thereof. ### Claim 3 (depends on 1) The method of claim 1, wherein the Type 1 tracer doesn't degrade in at least 100° C. for 3 to 6 months. ### Claim 4 (depends on 1) The method of claim 1, wherein the Type 2 tracer is a polymer having a polydispersity ranging from 1.0 to 1.5. ### Claim 5 (depends on 4) The method of claim 4, wherein the polymer has a molecular weight (Mw) ranging from 30,000 Da to 20,000,000 Da. ### Claim 6 (depends on 1) The method of claim 1, wherein the Type 2 tracer has a size that is larger than an inaccessible pore volume (IPV) in the hydrocarbon-bearing reservoir, wherein the IPV ranges from 10 to 50% of a total pore volume in the hydrocarbon-bearing reservoir. ### Claim 7 (depends on 1) The method of claim 1, wherein the Type 2 tracer is a polymer prepared via a controlled/living radical polymerization technique selected from the group consisting of reversible addition-fragmentation chain-transfer (RAFT), atom transfer radical polymerization (ATRP), activator regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP), and combinations thereof. ### Claim 8 (depends on 1) The method of claim 1, wherein the Type 2 tracer is a brine soluble polymer. ### Claim 9 (depends on 1) The method of claim 1, wherein the Type 2 tracer is a polymer including monomers selected from the group selected from saccharides, sulfonated monomers, hydroxylated monomers, zwitterionic monomers, fluorinated monomers, and combinations thereof. ### Claim 10 (depends on 1) The method of claim 1, wherein the Type 2 tracer comprises a zwitterionic/fluorinated copolymer selected from the group consisting of poly(1-vinyl imidazole-co-4-trifluoromethylstyrene), poly(3-(1-vinyl-1H-imidazol-3-ium-3-yl)propane-1-sulfonate-co-4-trifluoromethylstyrene), and poly(3-(1-vinyl-1H-imidazol-3-ium-3-yl)propane-1-sulfonate), and combinations thereof. ### Claim 11 (depends on 1) The method of claim 1, wherein the Type 2 tracer doesn't degrade in at least 100° C. for 3 to 6 months. ### Claim 12 (depends on 1) The method of claim 1, wherein the breakthrough of the Type 1 tracer is slower than the breakthrough of the Type 2 tracer. ### Claim 13 (depends on 1) The method of claim 1, wherein the detecting a breakthrough of the Type 1 tracer and a breakthrough of the Type 2 tracer in produced fluid is performed by standard analytical chemistry techniques selected from the group consisting of solid phase extraction (SPE), gas chromatography-mass spectroscopy (GC-MS), high performance liquid chromatography (HPLC), and combinations thereof. ### Claim 14 (depends on 1) The method of claim 1, wherein the comparing the breakthrough of the Type 1 tracer and the breakthrough of the Type 2 tracer is performed using an Ensemble Smoother with Multiple Data Assimilation with Tracers (ES-MDA-Tracer) algorithm. ### Claim 15 A method of reconstructing inter-well porosity of a hydrocarbon-bearing reservoir using Type 1 tracer breakthrough data and Type 2 tracer breakthrough data, the method comprising: obtaining an initial reservoir model; performing reservoir simulation using the initial reservoir model to predict hydrocarbon production rate, water production rate, Type 1 tracer breakthrough data, and Type 2 breakthrough data from a producer well; obtaining a real field hydrocarbon production rate, real water production rate, real Type 1 tracer breakthrough data, and real Type 2 tracer breakthrough data from the producer well; and performing data assimilation by comparing real field production, real field Type 1 tracer breakthrough data, and real field Type 2 tracer breakthrough data with the predicted production, the predicted Type 1 tracer breakthrough data, and the predicted Type 2 tracer breakthrough data obtained from the reservoir simulation using the initial reservoir model. ### Claim 16 (depends on 15) The method of claim 15, wherein the Type 1 tracer is a passive tracer. ### Claim 17 (depends on 15) The method of claim 15, wherein the Type 2 tracer is a porosity-sensitive tracer. ### Claim 18 (depends on 15) The method of claim 15, wherein the Type 1 tracer breakthrough is slower than the Type 2 tracer breakthrough.