EARLY DELIVERABILITY EVALUATION OF NATURALLY FRACTURED CO2 GAS RESERVOIR WITH BOTTOM-WATER
天然裂缝性底水驱CO_2气藏产能早期评价――以阳5潜山CO_2气藏为例

Buried hill Y5 gas reservoir with bottom water has a high CO_2 content of 92.88%~99.80%, in which structural fractures and solution cavities are relatively developed. On the basis of testing data of three times, this paper analyzes well testing characteristics of the reservoir. 1) Through comparison between observation results of flowing pressure & temperature gradients and lab analysis, it could be seen that phase behavior of flowing CO_(2)column has obvious difference with that of static one. Under the circumstances of above critical conditions of CO_2, high-density fluid, including liquid water, gaseous CO_2 and hydrates, has been appearing in the well bore. Liquid state CO_2 begins to be formed at the depth of 265.80 m or so, when critical conditions are reached. Influenced by those, pressure loss in well bore is severe comparatively. 2) Per-well gas rate is relatively low and the base of stable production is obviously poor. And, 3) Commingled production of two layers could remarkably reduce gas deliverability. Finally, reasonable initial per-well gas rate are discussed from many aspects, and major measures to increase gas rate are put forward, that is, reducing pollution through adoption of acidizing reservoir to dissolve blockage and improve capability of gas flow carrying liquid by introduction of slim tubing to increase velocity of flow in the well bore.