Oil & Gas Geology ›› 2005, Vol. 26 ›› Issue (6): 711-716.doi: 10.11743/ogg20050602

Previous Articles     Next Articles

Time-space structure of reservoiring elements and hydrocarbon enrichment—concurrently discussing near-source reservoiring

Zhou Xingxi   

  1. Research Institute of Petroleum Exploration and Development, PetroChina, Beijing
  • Received:2005-08-20 Online:2005-12-25 Published:2012-01-16

Abstract:

Time-space structures of reservoiring elements and process influence the level of hydrocarbon enrichment.In plays that are adjacent to the source rocks and regional cap rocks,when the reservoiring occurred close to the hydrocarbon-generating period,the reservoirs would have relatively high hydrocarbon enrichment.Most of the major reservoirs in a basin or petroleum system belong to this type of reservoirs.Vertically,if there is no large and prominent tectonic events or depositional breaks between the source and reservoir rocks,we call it near-source combination,and its specific time interval is preliminarily determined to be no longer than an "Age"(in Mesozoic and Cenozoic)or an "Epoch"(in Paleozoic);otherwise we call it far-source combination. Laterally,near-source and far-source areas can be defined according to their location to be within or outside the effective source rock area—hydrocarbon kitchen.The available exploration results indicate that most of the discovered large and medium oil and gas fields in Tarim basin,such as Hadson oilfield,Lungu-Tahe oil/gas field,Kela 2 gas field and Yaha oil/gas field,are(indigenous-or)near-source combinations.Over 95% of the proved oil reserves in Songliao basin is distributed in Saertu,Putaohua and Gaotaizi oil reservoirs between the major source and cap rocks.Therefore,"near-source exploration" is an important and practical principle for discovering prolific oil and gas enrichment areas.Exploration of near-source oil and gas fields is commonly very fruitful.However,most of the near-source oil and gas fields are distributed in structural zones with high exploration difficulties,in complex plays or in deep and ultra-deep horizons of the exploration area,thus they are commonly discovered behind the "far-source" oil and gas reservoirs.

Key words: reservoiring element, time-space structure, near-source, hydrocarbon-generating period, reservoiring period

CLC Number: