含水饱和度对川西致密气藏水平井开发效果和经济效益的影响
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摘要
为进一步提高致密砂岩气藏高含水饱和度储量区的采收率,以川西致密砂岩气藏不同储层类型水平井为研究对象,通过测定岩心两相相对渗透率和数值模拟技术,分析了水平井生产动态特征、渗流规律及对采收率的影响,研究了含水饱和度对水平井开发效果及经济效益的影响。结果表明,水平井可采储量受含水饱和度影响明显,并受储层物性条件制约;不同物性条件下,含水饱和度对可采储量的影响程度不同。Ⅰ类优质储层孔喉发育、连通性好,原始地层水占据的孔隙空间小,驱替结束后残余气饱和度低,气相渗流能力强,受含水饱和度影响较小,生产能力强,采收率高;Ⅲ类差储层孔喉欠发育、喉道狭小,可动水饱和度低,渗流能力差,受含水饱和度影响明显,气井产量低,采收率低。在当前气价下,新场沙溪庙组气藏水平井经济极限含水饱和度为26.35%数67.50%。其中Ⅰ类储层部署水平井均具有较好经济效益;Ⅱ类储层在含水饱和度52%数55%范围内部署水平井可获得较好经济效益,在含水饱和度55%数62%范围内部署短轴水平井可获得经济利益;Ⅲ类储层在目前技术条件下部署水平井无任何经济效益。图8表4参15
In order to further improve the recovery efficiency of high water saturation area in tight sandstone gas reservoir,taking horizontal wells of different reservoir types in tight sandstone gas reservoirs in western Sichuan as research object,the effect of horizontal well production performance characteristic and seepage low on the recovery factor and that of water saturation on the development and economic benefit of horizontal well were analyzed through the determination of core two-phase relative permeability and the numerical simulation technology. The results showed that the recoverable reserves of horizontal wells were obviously affected by water saturation and restricted by reservoir quality. Under different reservoir condition,water saturation had different effects on recoverable reserves. The Ⅰ class of high-quality reservoir had well-developed pore structure and good connectivity,small pore space occupied by the original formation water,low residual gas saturation after displacement,strong gas phase permeability,small influence of water saturation,strong production capacity,and high recovery rate. The Ⅲ class of poor reservoir had underdevelopment pore structure,narrow throat,low mobile water saturation and poor seepage ability. This type reservoir was obviously affected by water saturation,as a result,gas well in this reservoirs had low production and low recovery efficiency. Under the current gas price,the economic limit water saturation of horizontal wells in Shaximiao formation was26.35%—67.50%. Horizontal wells deployed in classⅠreservoirs had good economic benefits. The Ⅱ class reservoirs could obtain better economic benefits within 52% —55% water saturation,and economic benefits could be obtained by deploying short shaft horizontal wells within 55%—62% water saturation. The Ⅲ class reservoirs had no economic benefit in deploying horizontal wells under current technical conditions.
In order to further improve the recovery efficiency of high water saturation area in tight sandstone gas reservoir,taking horizontal wells of different reservoir types in tight sandstone gas reservoirs in western Sichuan as research object,the effect of horizontal well production performance characteristic and seepage low on the recovery factor and that of water saturation on the development and economic benefit of horizontal well were analyzed through the determination of core two-phase relative permeability and the numerical simulation technology. The results showed that the recoverable reserves of horizontal wells were obviously affected by water saturation and restricted by reservoir quality. Under different reservoir condition,water saturation had different effects on recoverable reserves. The Ⅰ class of high-quality reservoir had well-developed pore structure and good connectivity,small pore space occupied by the original formation water,low residual gas saturation after displacement,strong gas phase permeability,small influence of water saturation,strong production capacity,and high recovery rate. The Ⅲ class of poor reservoir had underdevelopment pore structure,narrow throat,low mobile water saturation and poor seepage ability. This type reservoir was obviously affected by water saturation,as a result,gas well in this reservoirs had low production and low recovery efficiency. Under the current gas price,the economic limit water saturation of horizontal wells in Shaximiao formation was26.35%—67.50%. Horizontal wells deployed in classⅠreservoirs had good economic benefits. The Ⅱ class reservoirs could obtain better economic benefits within 52% —55% water saturation,and economic benefits could be obtained by deploying short shaft horizontal wells within 55%—62% water saturation. The Ⅲ class reservoirs had no economic benefit in deploying horizontal wells under current technical conditions.
引文
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[15]黎文清,李世安.油气田开发地质基础[M].北京:石油工业出版社,1993:379-385.
[2]郭平,景莎莎,彭彩珍.气藏提高采收率技术及其对策[J].天然气工业,2014,34(2):48-55.
[3]赵正果,王顺玉.低渗砂岩气藏提高采收率措施研究[J].天然气勘探与开发,2012,35(3):44-48.
[4]李华昌.川西致密气藏压裂水平井生产动态预测研究[J].钻采工艺,2015,38(3):63-65.
[5]王旭,谭明文,严小勇,等.新场气田沙溪庙组气藏JS21气层水平井开发效果评价[J].钻采工艺,2012,35(1):45-48.
[6]刘露,胡景涛,成晟,等.川西窄河道低渗砂岩气藏潜力分析[J].石油化工应用,2017,36(4):102-107.
[7]王凤娇,刘义坤.致密气储层压裂水平井产能影响因素排序[J].数学的实践与认识,2015,45(11):135-141.
[8]陈冠旭,程顺有,刘森,等.低渗透气藏水平井开发产能影响因素分析[J].地下水,2012,34(3):163-165.
[9]冯益富,原毅蕊.气藏水平井开发适应性评价指标研究[J].天然气技术与经济,2014,8(2):30-33.
[10]王军磊,贾爱林,何东博,等.致密气藏分段压裂水平井产量递减规律及影响因素[J].天然气地球科学,2014,25(2):278-285.
[11]余林瑶.苏里格气田水平井产能评价研究[D].成都:西南石油大学,2012:30-38.
[12]刘军.水平气井生产动态分析及配产制度研究[D].成都:西南石油大学,2015:10-18.
[13]陈汾君.低渗致密气藏压裂水平井产能及动态特征研究[D].成都:西南石油大学,2012:73-76.
[14]郑腊年.低渗透气藏水平井合理工作制度及稳产能力研究[D].成都:西南石油大学,2013:73-75.
[15]黎文清,李世安.油气田开发地质基础[M].北京:石油工业出版社,1993:379-385.