Research On The Production Decline Law Of Gas Wells In Volcanic Reservoir

Generally,the way of gas wells’ drilling is self-spraying because of gas characteristics of low viscosity,low viscosity and large expansion coefficient.In the past,research on the decline law of gas production was studied by the law of production decline reservoir.However,the law of production decline is not exactly the same,due to the differences of driving modes,fluid properties and seepage characteristics in gas reservoirs and reservoirs.Through the study of the geological and geological conditions of volcanic reservoirs in the XS gas field,such as stratum and tectonic features,type of gas reservoir space,lithofacies and sedimentary environment,this paper clarifies the vertical and horizontal distribution of volcanic reservoirs,pore permeability conditions,and the characteristics of gas and water distribution.Gas reservoir type and other basic conditions,combined with volcanic reservoir lithology changes,strong heterogeneity and complicated underground seepage conditions.At the same time,the dynamic features of gas field development were analyzed from the pre XSure,capacity,and gas-water characteristics systems,and the distribution laws of gas wells,reserves utilization,gas and water production,and overall gas well production in the XSA and XSB blocks were summarized.Finally,based on previous research results and on-site production actual conditions,the gas well production,production decline evaluation,and unobstructed flow rate evaluation method for gas wells were analyzed,and methods for decrements law analysis of gas wells with different development modes,such as definite production,pre XSure drop,and constant pre XSure production reduction,were determined.Based on the actual production data of gas wells in the XSA and XSB blocks,the relationship between gas well productivity over time,formation pre XSure,and the degree of production recovery was analyzed.And then determine the law of diminishing,scientific prediction of gas development index to provide the basis for determining the pre XSurization time of gas field development and production,and increase oil recovery to improve the economic benefit of gas field development.