7 Petroleum Source Rocks Upper Jurassic Smackover lime mudstone beds served as an effective regional petroleum source rockUpper Cretaceous Tuscaloosa Marine shale beds served as a local source rockUpper most Jurassic and Lower Cretaceous beds were possible source rocks
9 North Louisiana Salt Basin Cross Sections Location K’
10 North Louisiana Salt Basin Cross Section Well logs have been digitized. The types of logs used are SP and resistivity. Tops of each formation at individual well are recognized by well log signals. The strata thickness increases from updip to downdip. In the updip of the basin, parts of the Lower Cretaceous strata have been eroded.VE: 32X
11 Burial History Profile North Louisiana Salt Basin API:- Sediment accumulationrates were greatest in theJurassic ( ft/my)% of the tectonicsubsidence occurred in theLate Jurassic ( ft/my)Fastest subsidence rates late Jurassic and Early CretaceousMid-Cenomanian and Late Cretaceous Uplift resulted in slower subsidence ratesSubsidence increased in early PaleoceneSubsidence continued through Miocene, although at slower ratesPresent-day depths are maximum burial depths
12 North Louisiana Salt Basin, Sabine Uplift Cross Section VE: 22X
23 Thermal Maturation History Profile North Louisiana Salt Basin
24 Thermal Maturation Profile Cross Section North Louisiana Salt Basin Average Maturation Depth6,500ft12,000ft
25 Hydrocarbon Expulsion Profile North Louisiana Salt Basin Peak OilPeak GasTo adjust for the loss of organic carbon due to thermal maturation process, the original TOC values in the study area were estimated according to the method of Daly and Edman (1987) for thermal maturation modeling. The results show that original TOC was reduced by times during the thermal maturity process.
26 Thermal Maturation History Profile NLSB, Sabine Uplift
53 Schmoker (1994)The mass of hydrocarbons generated from a petroleum sourcerock can be calculated by using the following equations:1. (TOC wt%100)(FD)(VU) = MOG2. HI Original – HI Present = HG3. (MOG) (HG) (10-6kg/mg) = HCGWhere: TOC = total organic carbonFD = formation densityVU = volume of unitMOG = mass of organic carbonHI = hydrogen indexHG = hydrocarbons generated per gram of organic carbonHCG = hydrocarbon generated by source rock unit
56 NLSB Platte River Software — Gas Generated TOC = 1.0%Type II kerogenTransient heat flow6,400 TCFBy P. Li
57 NLSB Platte River Software — Gas Expelled TOC = 1.0%Type II kerogen1,280 TCFBy P. Li
58 MISB Platte River Software — Gas Generated TOC = 1.5%Type II kerogenTransient heat flow3,130 TCFBy P. Li
59 MISB Platte River Software — Gas Expelled TOC = 1.5%Type II kerogenTransient heat flow843 TCFSaturation threshold = 0.1By P. Li
60 Comparison of Hydrocarbon Generation & Expulsion Volumes Modified from Mancini et al. (2006b)
61 Gas Resource*Assuming that 75% of total gas calculated with the Platte River Software Approach is from late cracking of oilin the source rock.**Assuming a 1 to 5% efficiency in expulsion, migration and trapping processes.
68 ConclusionsIn the North Louisiana Salt Basin, Upper Jurassic and Lower Cretaceous Smackover, Cotton Valley, Hosston, and Sligo have high potential to be deeply buried gas reservoirs (>12,000 ft).In the Mississippi Interior Salt Basin, Upper Jurassic and Lower Cretaceous Norphlet, Smackover, Haynesville, Cotton Valley, Hosston, and Sligo have high potential to be deeply buried gas reservoirs (>16,500 ft).