Aggregation Conditions Of Water Soluble Gas And Its Potential In Lindian Area, Songliao Basin

Having made a detailed analysis about basic geologic data,aggregation conditions of water solube gas at home and abroad and having done something such as field investigation in Lindian area,pumping tests,water sample tests,gas sample tests and so on,we aim the ariticle to synthesize the data we got when undertaking the research on geology,pumping tests and the results of water as well as gas sample tests so as to analyze the aggregation conditions,estimate gas resource quantity and line out the range of profitability after conducting comparatively all-around research on geologic characteristics,aggregation conditions of water solube gas and geologic conditions of Lindian area.The core targets as follows:to line out the stratigraphic sequences of Songliao Basin,the evolution of sedimentary system,the characteristics of the basin floor and main faults,the aggregation conditions of water solube gas, estimation and types of water solube gas as well as the prediction of the range of profitability.The article focuces on factors mastering the aggregation of water solube gas,the catagories as well as quantity of water solube gas and predicting the range profitability of its aggregation in this range.Water solube gas,a kind of unconventional gas resources,is widely distributed on the earth.The study on water solube gas has just begun.Moreover,not until recent years,did some articles on such research appear,yet it is just in theory but does little work study on a specific range.Songliao Basin spans seven structural units including Western slope,Wu Yuer depression,Keshan—Yilong anticlinal belt,Heiyupao depression,Minglhui terrace,Suileng anticline and Suihua depression.On a whole, the western formation develops quite well,while the eastern part(the area to the east of Suileng anticline) develops not so well.Worse still,Nenjiang formation even Yaojia formation has begun to default,and technically speaking,the Tertiary defaults. The reservoir within the range develops rather well,and the layer has a good ability to produce water.Besides,both deep and mid-shallow source rocks had the process of generation and migration of gas,and also,reservoir pressure and degree of mineralization are good for gas to dissolve into water.Burring the research,I insist on starting from the large regional geological background,stick to analyzing it as a whole with some areas focused on so as to learn the structure of the target area from a larger scale and deeper levels.The stratigraphic sequence and distribution of the target ranges is better understood on the basis of a careful study about the structure of the ranges and evolution,which enables us to make a study about the reservoir property by studying the results and drilling data got by the people who started such research earlier;by means of field investigation,field tests and the analysis report of indoor water samples and has samples,we can make sure the dynamic parameter and congregating conditions of water solube gas in the range and its category,and finally manage to figure out the range of profitability with synthetizing the results.After a series of study on the target area,we draw the conclusions as follows:1,In the target area,Aggregation conditions of Water Soluble Gas are gas source, reservoir property,water quantity and degree of mineralization,trap and so on.The gas source and the degree of mineralization are the most important.2,In the target area,we know the type of water in Li3 well is NaHCO₃-type by analyzing the geothermal water quality,which shows a weak alkaline,the water in Li13,Lin8 and Huol well is CaCl₂-type.3,The main components of water-soluble gas is methane in the target area,a small amount of nitrogen,carbon dioxide and ethane.Among the components,the content of methane is 88.906%to 95.690%,nitrogen is 3.653%to 9.199%,carbon dioxide is 0.573%to 1.805%,and ethane is 0.061%to 0.083%.Therefore,the type of water soluble gas is methane gas in the study area.4,In the probability of 0.1,0.5,0.9,gas resource quantity of Saertu is 7.68×10¹⁰m³,5.44×10¹⁰m³,3.19×10¹⁰m³ in the study area,Putaohua is 1.08×10¹⁰m³,0.86×10¹⁰m³,0.65×10¹⁰m³,and Gaotaizi is 7.64×10¹⁰m³,6.21×10¹⁰m³,4.79×10¹⁰m³. The total quantity is 16.40×10¹⁰m³,12.51×10¹⁰m³,8.63×10¹⁰m³.5.The area from the Yul3 to Li3 Well is more favorable.In this region,Gas content reaches unsaturation to saturation(ranges from 0.6 to 2.17m³/m³),and the total salinity is about 5000mg/L,which locates near the oil/water boundary in the region.The gas resource is abundant;the number of the thickness water-gas-bearing formation is large and large capacity of water.In this area,the depth of the water-gas-bearing formation is relatively deeper(at the bottom of the Second and Third Member of Qingshankou formation,about between 2000 to 2200m),therefore, the pressure of water-gas-beating formation is relatively large in this area,which is beneficial to the gas dissolving,but aggregation conditions is ordinary.In addition,the areas from the Huol to Huo6 Well and from Yul to Yul9 Well are more favorable.The main features of the two areas are that structural traps develops quite well,which is very beneficial to local aggregation of the water soluble gas.Judging from the preservation conditions,the northeast region is better than southwest in the area.