Lu T.,Petrochina |
Lu T.,State Engineering Laboratory of Low Permeability Oil and Gasfield Exploration and Development |
Zhang J.,Petrochina |
Zhang J.,State Engineering Laboratory of Low Permeability Oil and Gasfield Exploration and Development |
And 10 more authors.
Natural Gas Industry
Typical tight gas reservoirs in the Sulige Gas Field, Ordos Basin, are characterized by low permeability, low pressure, low abundance, thin layer and strong heterogeneity, so it is tough to efficiently and economically develop this field due to a quick drop in formation pressure and a rather low single-well production. In view of this, the PetroChina Changqing Oilfield Company has tackled with many technical problems since 2001, among which the fine description method was developed for characterizing the geological properties of such typical tight sand gas reservoirs in the Sulige Gas Field. Besides, aimed at thin layers with strong heterogeneous sandstone reservoirs, a series of technologies has been established, such as horizontal well development geology, rapid drilling techniques, reservoir stimulation by multi-fractured horizontal wells, etc. The application results of horizontal wells show that the drilling rate reaching target zones increased from initial 23% to current above 60%; single well production reached more than 5×104 m3/d, which is 3-5 times that of adjacent vertical wells. Thus, an integrated horizontal well development zone was built, and the development mode was then successfully transformed, as a result, an obvious rise was seen either in the development level or the development profit in this field. This successful case not only proves that the horizontal well development technology is an important technical way for the efficient and cost-effective exploitation of tight sand gas reservoirs, but reveals that tight sand gas reservoirs are prospective in the future with the aid of appropriate development technologies. Source