X水驱气藏合理采气速度研究

发布时间：2018-12-18 19:18

【摘要】：水驱气藏储量在我国已投入开发气藏储量中占一半以上,大多数非均质性强、水体能量大及采气速度高的水驱气藏开发过程中均存在不同程度的水侵,严重制约气藏的开采效果。因此必须对水体运动规律进行研究,综合考虑各种因素的影响,确定合理的采气速度,防止气藏过早水淹,以保证水驱气藏合理高效的开发。海上X水驱气藏各井区采气速度合理界限认识不清,影响因素不明确,对采收率影响效果认识不清晰。为此,本文针对目标气田地质特征,开展了国内外类似气藏采气速度及开发效果调研,采用气藏工程法和数值模拟法,对目标气田水体运动规律、单井配产极限等影响采收率的主要因素及合理采气速度进行了研究,取得了如下成果：(1)对国内外类似水驱气藏的调研结果表明：类似气藏平均采气速度为5%～6%左右,采收率为60%～75%左右；在生产初期,应合理控制采气速度,见水后,应及时调整采气速度,使气井保持“三稳定”生产。(2)运用出水特征分类方法,分析了目标气田产水气井出水类型。通过对地质及生产状况进行分析,认为CHX1井区水侵方向为气层下部底水水侵,CHX3井区水侵方向为南、北两翼边水水侵。采用多种方法对目标气田水侵强度进行了分析,认为目标气田为中强弹性水驱。采用非稳态水侵模型计算出X气藏CHX1井区目前水侵量为70.93×104m3,CHX3井区水侵量为198.22×104m3。(3)对目标气田进行气井目前无阻流量、气井临界携液流量及气井临界产量计算后,分析发现：各井目前配产比例为无阻流量的10%～30%,均较为合理；A10井产量与临界携液流量相接近,井底可能有积液,其余井产量均高于临界携液流量；各井区产气量高于临界产量的气井,均已产水；产气量低于临界产量的气井,目前生产稳定。(4)对目标气田进行剖面模型机理分析认为：采气速度越大,模型采收率越低；底水模型中气井避水高度越高,气井采收率越高；边水模型打开程度越高,采收率越高。(5)建立目标气田数值模拟模型,并进行历史拟合,在气藏合理配产界限基础上制定多套方案,对比预测指标,结合类似气藏调研成果,确定CHX1井区合理采气速度为2%,CHX3井区合理采气速度应调整为4%。
[Abstract]:The water drive gas reservoir reserves account for more than half of the developed gas reservoirs in China. Most of the water drive gas reservoirs with strong heterogeneity and high water energy and high gas recovery rate have different degrees of water invasion during the development process. The production effect of gas reservoir is seriously restricted. Therefore, it is necessary to study the law of water body movement, consider the influence of various factors synthetically, determine the reasonable gas recovery speed, prevent the gas reservoir from flooding prematurely, so as to ensure the reasonable and efficient development of the water drive gas reservoir. The reasonable limit of gas recovery velocity in each well area of offshore X water drive gas reservoir is not clear, the influencing factors are not clear, and the effect of oil recovery is not clear. In this paper, according to the geological characteristics of the target gas field, the gas recovery rate and the development effect of similar gas reservoirs at home and abroad are investigated, and the moving law of the water body of the target gas field is studied by using the gas reservoir engineering method and numerical simulation method. The main factors affecting oil recovery and reasonable gas recovery rate, such as the limit of single well production, are studied. The results are as follows: (1) the investigation results of similar water-drive gas reservoirs at home and abroad show that the average gas recovery rate of similar gas reservoirs is about 560% and the recovery factor is about 60%; In the early stage of production, the gas recovery rate should be controlled reasonably, and the gas recovery rate should be adjusted in time after water meeting, so that the gas well can keep "three stable" production. (2) by using the method of classification of the effluent characteristics, the type of water produced from the water well produced by the target gas field is analyzed. Based on the analysis of geology and production conditions, it is considered that the direction of water invasion in CHX1 well area is the bottom water invasion of lower gas reservoir, and the direction of water invasion in CHX3 well area is south and north flanks. Several methods are used to analyze the water invasion intensity of the target gas field, and it is considered that the target gas field is medium strong elastic water flooding. By using the unsteady water invasion model, it is found that the current water invasion rate in the CHX1 well area of X gas reservoir is 70.93 脳 104m3HX3 well area, which is 198.22 脳 104m3. (3) after calculating the current unhindered flow rate of the gas well, the critical fluid carrying rate of the gas well and the critical production rate of the gas well. It is found that the proportion of production in each well is 10 / 30 of unobstructed flow at present, which is more reasonable; The production rate of well A10 is close to the critical fluid carrying flow rate, and there may be liquid accumulation at the bottom of the well, while the production of other wells is higher than the critical fluid carrying flow rate, and the gas wells with higher gas production rate than the critical fluid flow rate in each well area have already produced water. The gas production rate is lower than the critical production rate, and the production is stable at present. (4) the model mechanism analysis of the target gas field shows that the higher the gas recovery rate, the lower the model recovery; The higher the water escape height of the gas well in the bottom water model, the higher the recovery rate of the gas well. The higher the opening degree of the edge water model, the higher the recovery efficiency. (5) the numerical simulation model of the target gas field is established, and the historical fitting is carried out, and on the basis of reasonable distribution and production limit of the gas reservoir, several sets of schemes are worked out, and the prediction indexes are compared. Based on the investigation results of similar gas reservoirs, it is determined that the reasonable gas recovery rate in CHX1 well area should be adjusted to 4.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TE377

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