摘要
低渗致密砂岩含水气藏具有大面积分布、低构造、低孔渗、强非均质性,次生孔隙发育,孔喉细小,毛细管压力高,无明显的气/水界面,气水关系复杂,含水饱和度高等储层特征。储层渗流机理复杂:储层水相对气相渗流能力影响显著;在气水互封状态下,气体弹性膨胀导致部分束缚水转化为可动水;气、水两相渗流能力受压力梯度影响,压力梯度增大,气相渗流能力降低,水相渗流能力升高。基于储层特征及渗流机理认识,提出了针对性的开发对策:①加强富集区优选,从储量大小、储量动用性和动用速度三个角度出发,结合储层静、动态特征,形成相应的储层评价方法,在此基础上结合地质特征,优选富集区,实现有序、滚动开发;②根据储层可动水饱和度分布,优选井位、射孔层位,降低产水风险;③依据临界储层厚度图版,选择合适井型;④采用密井网开发;⑤控压开采;⑥根据储层性质,合理配产;⑦提升压裂酸化增产改造水平,开发低伤害压裂液;⑧采用空气钻井或负压钻井,降低地层伤害;⑨对于产水气藏,强化排水采气,建立"要采气,先排水"的开发思路;⑩增压开采,提高采收率。
Low permeability and tight sandstone gas reservoirs had the characteristics of large distribution area , low structure , low porosity and permeability , strong heterogeneity , development of secondary porosity , small pore throats , high capillary pressure , and no obvious gas/water interface , complex relation between gas and water with high water saturation.Reservoir percolation mechanism was complex.Gas percolation ability was influenced obviously by water.Under the gas-water sealing condition , the gas elastic expansion would induce some irreducible water turning into movable water.Gas-water two-phase seepage ability was affected by the pressure gradient.When the pressure gradient was raised , gas flow capacity was reduced , while water seepage ability was raised.Based on the understanding of reservoir characteristics and percolation mechanism , the following development strategies are puts forward : which include①enrichment zone optimization should be enhanced.the enriched region is optimized for orderly and rolling development by reservoir evaluation methods of establishing static and dynamic reservoir characteristics , and in consideration of the size of reserves , the reserves producing and its producing velocity ; ②according to the reservoir water saturation distribution , well location and perforation horizon are optimized to reduce water production risk ; ③based on the chart board of critical reservoir thickness , appropriate well type is selected ; ④ dense well pattern is used for development ; ⑤oil production is performed by pressure control ; ⑥according to the reservoir properties , reasonable production allocation is deployed ; ⑦fracturing and acidizing reconstruction level should be improved by the development of fracturing fluids with low damage ; ⑧air drilling or negative pressure drilling is used for reducing formation damage ; ⑨in water and gas produced reservoirs , gas recovery is strengthened by water drainage , the idea of ' water being drained before gas production is established ; ⑩gas recovery is enhanced by pressure-boosting stimulation.
出处
《石油天然气学报》
CAS
CSCD
2013年第7期93-99,3+2,共7页
Journal of Oil and Gas Technology
基金
国家科技重大专项(2011ZX05013-002)
关键词
低渗致密气藏
渗流机理
富集区优选
合理配产
排水采气
增压开采
开发对策
low permeability tight gas reservoirs
percolation mechanism
optimizing oil enriched area
reasonable production allocation
water drainage and gas recovery
production by pressure-boosting
development strategy
