The Evaluation Of Formation Pressure And Dynamic Reserves In Eastern-Sulige Gas Field

Eastern-Sulige gas field has experienced extensive development and management in recent 10 years.It seems difficult to provide accurate data support for the development and adjustment of Eastern-Sulige gas field,owing to the inaccurate cognitions of formation pressure and dynamic reserves.Therefore,it is necessary to conduct in-depth study on the evaluation methods of formation pressure and dynamic reserves in Eastern-Sulige gas field.Based on the existing evaluation methods of formation pressure and dynamic reserves,this paper selects the suitable evaluation methods of formation pressure and dynamic reserves in Eastern-Sulige gas field,evaluates the key parameters such as formation pressure and dynamic reserves accurately,carries out the evaluation of economically recoverable reserves on this basis,and puts forward the prediction mathematical model of gas field development index.The results in this treatise have great guidance for accurately obtaining the formation pressure and dynamic reserves of Eastern-Sulige gas field.The main contents of this treatise include the following aspects:(1)The existing evaluation methods of formation pressure are investigated,and the adaptability of different evaluation methods in Eastern-Sulige gas field is analyzed.The formation pressure is comprehensively evaluated by four methods,including material balance method,wellhead pressure conversion method,quasi-stable mathematical model evaluation method and modern production instability analysis method.The variation characteristics of formation pressure over the years,pressure drop and plane distribution characteristics of gas production per unit pressure drop are analyzed,and the influence of different parameters on gas production per unit pressure drop is analyzed.(2)The existing dynamic reserves evaluation methods are investigated.The adaptability of material balance method,empirical formula-pressure drop curve method,production accumulation method,modern production instability analysis method and other dynamic reserves evaluation methods are analyzed.On the basis of the above methods,the dynamic reserves of single well in Eastern-Sulige gas field are evaluated accurately.The planar distribution characteristics of the block dynamic control reserves are analyzed,and the classification and evaluation of gas recovery wells in Eastern-Sulige gas field are carried out by using the classification results of single well dynamic control reserves,and the main engineering and geological factors affecting the reserves are analyzed.(3)The analysis method of the existing abandonment pressure is investigated and the economic productivity equation-the bottom hole flow pressure method,the experience value method and the gas reservoir depth calculation method are used to determine the abandonment stratum pressure in Eastern-Sulige gas field.The size of the economic recoverable reserves of the single well is determined.(4)On the basis of the existing economic recoverable reserves evaluation,the economic recoverable reserves prediction model is established by using the mathematical model of Spearman and GM correlation.The reliability of the Spearman and GM prediction model is demonstrated.The prediction model established in this paper has certain guidance for the prediction of the economic recoverable reserves in Eastern-Sulige gas field.At the same time,it has a certain reference value for the prediction of economically recoverable reserves of similar gas reservoirs at home and abroad.