Study Of Dynamic Reserves' Evaluation Technique And Development Strategies For "Four-high Characteristics" Gas Reservoirs

The "Four-high Characteristics" gas reservoirs refer to an abnormally high temperature and high pressure gas reservoirs with high irreducible water saturation and high CO2 gas content.Nowadays,these kinds of reservoirs account for larger portion than previous times.The integration of the "Four-high" characteristics has a prominent influence on the dynamic laws of gas fields' development so that the conventional dynamic analysis methods are no longer applicable.To solve this problem as well as providing reference,based on a large number of domestic and foreign relevant references,this paper took China's typical"Four-high Characteristics" gas reservoir A as a target area and studied respectively from relevant experiments,dynamic reserves'assessment technology,numerical simulation technology and development policies' formulation,etc.Firstly,after analyzing the main geological characteristics of gas reservoir A,this paper collated relevant data(including high temperature and pressure gas fields' seepage mechanism experiments and fluid experimental results;material balance equation establishment methods for high pressure gas reservoirs;establishing methods of numerical simulation models and development strategies,etc.)of developed gas reservoirs at home and abroad which are similar to the characteristics of gas reservoir A in order to provide reference for the follow-up research work;Secondly,this article utilized representative fluid and core samples to carry out experimental studies on "seepage mechanism,fluid PVT parameters variation law and fluid content variation rule" thus clarifying the change trend of relative parameters for dynamic reserves calculation.Furthermore,accurate experimental data were provided for the establishment of numerical simulation models and the formation of development strategies.Thirdly,this article established a new material balance equation for the "Four-high Characteristics" gas reservoir A,within which the water intrusion,water vapor content and expansion of gas reservoirs,stress-sensitive effect and dissolved gas release effect were taken into account.Moreover,this paper verified the applicability of the new equation through the"special factors impact analysis" and "real example calculations and comparative analysis".Fourthly,this paper took use of Schlumberger's ECLIPSE numerical simulation software to establish the numerical calculation model for gas reservoir A,within which special factors such as "formation water evaporation,water-dissolved gas's release,and stress sensitivity"were taken into account.Moreover,based on the established model,this article studied the development strategies of the target gas reservoir A and obtained some reasonable strategies.