THE APPLICATION OF N-ALKANE'S ODD-EVEN CARBON NUMBER PREDOMINANCE IN OIL-SOURCE ROCK CORRELATION——AN EXAMPLE OF THE LOWER PALEOZOIC IN TARIM BASIN

The composition and distribution of the carbon number of n-alkane can reflect the source of organic matters,sedimentary environment and maturity of organic matter.Comparision of the n-alkane's GC diagrams in Tazhong Low Uplift shows that odd-carbon predominance appears in the Upper Ordovician source rocks,and even-carbon predominance has taken on in Cambrian-Lower Ordovician source rocks.The result of oil-source rock correlation shows that the origin of oils in the fields of Well TZ 10-11-12 is the Upper Ordovician source rocks,and the oils of Well TZ 45 and Well TZ 162 are from CambrianLower Ordovician source rocks.And the strata corresponding to the crude oils with odd-even carbon number predominance is accorded with what the oil-source rock correlation shows.In a word,the characteristics of n-alkane's odd-even carbon number predominance can be as an effective method for oil-source rock correlation in Tazhong Low Uplift,Tarim Basin.