Focus of the issue: replenishment of stocks
Complex Study of Sedimentary Basins is the Basis for Effective Forecast of the Oil and Gas Content in New Territories
Iskaziyev K.O., Karabalin U.S., Azhgaliyev D.K.Forecast of the oil and gas content in new territories and expansion of the resource potential on the basis of the oil and gas field exploration is one of the key objectives of the oil and gas industry. It is commonly known that in 2012 Kazakhstan achieved the oil production level equal to 80 million tons. It is expected to increase this indicator by 1.5-2 times in the coming ten years according to the long-term development plans.
The overall appraisal of the forecasted geological and recoverable resources in the country according to expert data is about 20 billion tn. and 7 billion tn. respectively. Considering the planned production levels the optimal annual increase of recoverable resources for reserves replenishment should not be less than 100 million tn.
The outlined delay in systematic replenishment of hydrocarbon resource potential and in timely preparation of conditioned local drilling facilities was caused by lack of study of subsoil and sedimentary basins within the last 20 years. Consequently the study of internal structure and prospects of sedimentary basins were of unsystematic and incomplete nature due to external factors. The works were primarily carried out within the separate local sites and contract territories and, as a rule, nearby the known and producing oil-and-gas fields and developed infrastructure.
In its turn the systematic study of prospects with various areas was complicated by lack of full-scale analysis of new geologic-geophysical data caused by limited access of opportunities. It should be noted, that a significant volume of new geologic-geophysical information accumulated for the previous period (1991-2011) has not been subjected to timely and comprehensive analysis and generalization. As a result all these factors impacted on quality and success of exploration works, which consequently restrained the reasonable increase in forecasted resources, reserves and discovery of new oil and gas fields.
In this regard and in order to renew the systematic study of prospects and sedimentary basins in 2009 a number of works on the "Comprehensive Study of Sedimentary Basins of the Republic Kazakhstan" Project (hereinafter - the Project) were initiated.
The project-related surveys were conducted by the initiative of the Geology and Subsoil Use Committee and JSC “NC “KazMunayGas”. JSC “Kazakh Institute of Oil and Gas” and the Consortium comprised of the following Kazakhstan consulting companies: “AkAy Consulting” LLP, " SPC TuranGeo", "Geoken", RSE "Specialized Gravimetric Enterprise", “Geomunay XXI” LLP, "KazNIGRI", "AktubNIGRI" and "Oil-Geoconsulting" participated in the Project.
The survey covered all 15 sedimentary basins (scheme) including 5 major oil and gas basins (the Caspian Sea, Usturt-Bozashinsk, Mangyshlak, South Torgay and Shu-Sarysu basin) and 10 undeveloped frontier basins (Aral, Syrdarya, Balkhash, Teniz, Priirtysh, Zaysan, Alakol, Ili, North Kazakhstan and North Torgay basin).
The survey included a full-scale comprehensive study, re-appraisal of internal structure, volume of forecasted resources, clarification of potential of the oil and gas content and justification of local prospects for exploration works.
At present the Project related works have been completed. In general, available geological and geophysical data has been summarized, analyzed and digitized; regional structural imaging made to a single form and standards; data from all major physical fields and direct exploration methods have been re-interpreted. In particular the Caspian Basin area is covered with a new high-precision aeromagnetic survey.
As a result of modern analysis and distribution of abnormalities the new data on areal and deep-earth allocation of magnetic sites linked to such abnormalities of potential local structures and sites have been obtained. The local sites have been analyzed and ranged and a stock of prospects has been specified. Based on this the quantitative appraisal of the oil-and-gas content prospects and data on oil and gas forecasted resources have been updated.