Xinjiang Oilfield Low Permeability Porous Reservoir Unused Reserves Evaluation And Development

By the end of 2002, PetroChina Xinjiang Oilfield Company has found low permeability and porous reservoir with non-producing reserves of 20,950x10 t (OOIP), accounting for 39% of the total non-producing OOIP of it, this type of reserves is distributed in four areas such as northwestern margin, eastern part, hinterland and southern margin of Junggar Basin, which fall into 14 oil-gas fields or 38 blocks. From the distribution of target zones, these reserves are primarily distributed in Jurassic, Triassic and Permian.The non-producing reserves are mainly characterized by poor petrophysical property, low reserve abundance and large variation of reservoir buried depth, etc.This paper presents an evaluation of non-producing reserves of low permeability and porous reservoir in PetroChina Xinjiang Oilfield Company by means of the method adopted by PetroChina Corp. The result shows that in this type of reserves there exist no reserves to be reviewed after verification and untabulated reserves exept for proved reserves (19158譴04t) and reserves to be proven (1792譴04t). In proved reserves , producible reserves in the near future could be 1062譴04t with low benefit A-class reserves of zero and B-class reserves of 738譴04t, as well as temporary non-benefit reserves of 17358譴04t.As can be seen from these evaluated results, the majority of the above non-producing reserves has no economic performance by applying conventional exploitation processes. How to make this part of hard producible reserves mobile is undoubtedly to be significant and basic issues for sustainable development of the enterprise. Hence, the study provides the research result of typical block development and uses advanced productive reserves technologies and achievements at home and abroad for reference. The following measurements for similar reservoir development are suggested hereby: 1) In-depth study of the reservoir qualities to improve producible extent of proved reserves. 2) Optimizing relative high-yielding areas to implement local development. 3) Adopting advanced and practical technology to improve development performance , and 4) changing mode of present management to speed up development of hard producible reserves.