Prediction And Resource Evaluation Of Heavy Oil In Global Priority Areas

The exploration and development of unconventional oil and gas has become a more effective solution forthe rising of global oil demand and the ultimate limit of global conventional oil and gas resources.The heavy oil resources have become an important research direction due to their wide distribution and huge resources.Scholars have done a lot of research work on worldwide heavy oil resources.Different research institutions and individuals have used different methods to evaluate and predict heavy oil resources.However,some defects have been found,such as the divergence on the definition of heavy oil,the limitations of the evaluation methods which are mostly simple statistics and mathematical model deduction,the premature date and incomplete parameters of evaluation.Through using relatively comprehensive and new parameters and reasonable evaluation methods,this study conducted a new evaluation of heavy oil resources in priority areas of the world(except the Americas).Combined with the evaluation results,the characteristics of distribution and the strategic regions of heavy oil are summarized,which can provide reference for the follow-up study and make suggestions for heavy oil exploration and development.In this paper,the definition index of heavy oil is redefined.It is considered that the first index of heavy oil is API(American Petroleum Institute Gravity)(10°-25°)and the second index is viscosity(100-10000 cP).Two new methods of resource evaluation are derived from volumetric method by using computer and network:the grid method and the volumetric method shown by probability distribution of parameters.The application limitand recovery rate of five mining technologies are determined(Recovery rate:SF:35-75%,SAGD:40-75%,N-solv:40-75%,CP:10-20%,CSS:15-25%).The technology with high recovery rate such as SF has a high requirement for properties of heavy oil,while the CP with low recovery rate requires relatively low requirements and is generally applicable.According to the uniform standard,the resource evaluation parameters of 47 heavy oil basins in the world(except the Americas)were extracted systematically,including the burial depth,thickness and oil saturation of heavy oil reservoirs,et al.,which can be the basic data for scientific and reasonable evaluation of global heavy oil resources.According to the prediction of favorable area and resource evaluation of 47 heavy oil basins in the world(except Americas),the in-place resources and the technical recoverable resources of 47 heavy oil basins are 3341.2×10~8t and 926.7×10~8t,respectively.The Central Arabian Province(Basin)and the Western Arabian Province(Basin)(They are also collectively referred to the Arabian Basin)have the largest in-place resources.The technical recoverable resources in the top three are the resources of the Western Arabian Province(Basin),Volga-Urals Basin and Central Arabian Province(Basin).The metallogenic model of heavy oil can be divided into the types of slope degradation,paleo-reservoir damage,tectonic uplift and fault dispersal.Slope degradation and fault dispersal are dominant.Heavy oil resources are mainly distributed in shallow Jurassic-Neogene strata in passive continental rift basins and foreland basins of the Middle East and Western Russia.The distribution area of heavy oil can be divided into five zones according to the geological structure characteristics,namely,the Arabian plate area,the Ural Mountains area,the Eurasian narrow zone,the Pacific coastal zone(West Bank)and the African marginal zone.After comparing the scores,the global strategic regions of heavy oil were selected.The best selection is Middle East and Central Asia-Russia.The best evaluation units are the Western Arabian Province(Basin)Cretaceous Unit,Central Arabian Province(Basin)Jurassic Unit,Volga-Urals Basin Carboniferous Unit,Precaspian Basin Cretaceous Unit,Western Arabian Province(Basin)Triassic Unit and Central Arabian Province(Basin)Cretaceous Unit.