深盆气成藏平衡作用及边界地质条件研究

Deep basin gas, or basin-centered gas accumulations can notably distinguished from normally trapped ones on their mechanism, behavior and distribution rules. The equilibrium processes are very important to infect directly.the prognostication of deep basin gases. The item “studies on the equilibrium processes and critically geological conditions” was carried out and accomplished mainly on experiments and basin analyses. The harvests include mainly that as following..(1) Gas-water driving model for deep basin gas accumulation was established..The migration was divided into two typical models, one is piston model driven by the expansibilities of gas, and another is displacement model driven by buoyancy of gas. The former accumulates deep basin gas and the later traps normal gas. Based.on the analysis, spectrum on gas formation and distribution was proposed. (2) The conditions, mechanic process and equations on dynamic equilibriums for deep basin.gas accumulations were analyzed and dynamic equilibrium equations were established.The flux of pore water is a critical factor to determine the accumulation for deep basin gas. (3) Based on experiments, we made certain that the critical conditions.for water over gas are respectively o.5cm by glass tubes and 0.35-0.4mm of sand diameters by sand model experiments. It was stricter in 3-dimension imitation than 0.05mm of sand diameters. (4) Abnormal pressure model of deep basin gas was established. (5) Proposed the methods for deep basin gas prognostication, such as the principals of high potential, and spectrums et al..The conclusions will be very useful for the theory research and gas exploration.further. They are foundations to recognize deep basin gas further.

深盆气在成藏机理、表现方式和分布规律等方面明显有别于常规圈闭气藏。本项目拟主要从物理模拟实验分析入手，结合数值模拟分析以及典型盆地区的深盆气成藏条件解剖，对深盆气成藏过程中的平衡作用原理、方式、主要控制因素以及成藏临界（边界地质）条件展开分析和研究。研究成果将对我国的深盆气资源估计和天然气发展战略的制定具有重要意义。