Crude oils origins

Sulfitr and nitrogen contents in 550°C uacaum residues according to crude oil origin. Source Total. 

The principal constituents of most crude oils are hydrocarbon compounds. All hydrocarbon classes are present in the crude mixture, except alkenes and alkynes. This may indicate that crude oils originated under a reducing atmosphere. The following is a brief description of the different hydrocarbon classes found in all crude oils. 

Crude Petroleum. This method, in principle, should be applicable to all carbonaceous materials regardless of origin. Preliminary C13 measurements made on a sample of Ponca City crude oil (original petroleum of Project 6, American Petroleum Institute) yielded an aromaticity value of 0.15. 

Crude oil origin Asphaltenes (wt. %)d Nickel Vanadium Iron... 

Crude oil origin. . . Residuum type. Vacuum Gas Oil Atmospheric Vacuum (east) Atmospheric Burzurgan Boscan Atmospheric Vacuum California Vacuum Cabimas Vacuum... 

Organic sulfur compounds (e.g., mercaptans, sulfides, polysulfides, thiophenes) are present in petroleum products to a greater or lesser extent depending on the crude oil origin and the refinery treatment. The sulfur content of fuel oil (ASTM D-396) can be determined by a variety of methods (ASTM D-129,ASTM D-1552, ASTM D-2622, ASTM D-4294, IP 61, IP 63), with mercaptan sulfur in cracked stocks being particularly necessary for evaluation (ASTM D-3227, IP 342). 

The storage stability of fuel oil may also be influenced by the crude oil origin, hydrocarbon composition, and refinery treatment (especially if unsaturated constituents are present). Fuel oil containing unsaturated hydrocarbons has a greater tendency to form sediment on aging than the straight-run fuel oils. Unsaturated hydrocarbon constituents can be determined by the bromine number. (ASTM D-1159, ASTM D-2710, IP 130). 

Paraffinic base oils of very high viscosity index are also manufactured by severe hydrotreatment or hydrocracking processes. Section 1.5, in which isoalkanes are created by chemical reaction and their crude oil origin is of reduced importance. 

Conventional (primary and secondary) recovery methods recover only a small fraction of the crude oil originally in place in a typical reservoir. The primary and secondary recovery techniques, which include pressure maintenance by gas injection and water flooding for improved recovery, leave approximately two-thirds of the original oil in the reservoir. As the conventional oil production of the United States continues to decline, enhanced oil recovery will play an important role in the utilization of our domestic resources. Conventional methods do not overcome the basic problems of oil being trapped within the rock pores and of the low mobility of the remaining oil. 

Within the limitations imposed by the determination of trace elements in the total crude oil, when their concentration is essentially confined to a variable portion of the total crude oil, we may conclude that the contents of the trace elements S, V, Cl, Na, Ni, Zn, Co, Mn, Se, Br and As are controlled by maturation processes rather than migration processes, though this may simply reflect maturation of the asphaltene fraction of the crude oils. S, V, Se and Ni account for more than one quarter of the cumulative variance and represent metallo-organic compounds. The factor analyses further demonstrate not only the -efficacy of our separation systems between crude oil and entrained formation water, but show that it is most unlikely that the Fe present in the crude oils originates from corrosion products incorporated during production. Four elements, Fe, Mn, As and Co represent essentially unique factors. Finally, it is clear that considerably more work.is justified on trace elements in crude oils, particularly in relation to their distribution within the various fractions and in relation to interactions between organic and inorganic components. 

---