摘要
大牛地气田2014年投产水平井稳产至今,并未出现明显的产能递减,其递减规律和以往历年投产井的结果及国内外同类气藏的开发结果出现明显差异。对这一部分水平井和之前历年投产井进行了对比分析,并将其稳产原因分为地质原因、工程原因和管理原因3大类。其中地质原因包括储层产水、水平井钻遇砂岩长度和储层生烃强度等因素;工程原因主要指压裂设计和施工的因素;管理原因主要包括排水采气思路和配产思路的转变。研究结果表明:产水对致密气藏气井生产具有控制作用,产水量越低,气井越容易稳产。气测显示砂岩长度和储层生烃强度越高,越有利于气井稳产。压裂规模越大、返排率越高,越有利于气井稳产。对于高含水致密气藏来说,排水是开发第一要务,应确立"排水和采气同等重要、同步进行"的整体开发思路。在保证排水的情况下降低配产比例,可以有效降低投产初期储层压降速率,更有利于气井的稳产。同时提出,对于致密气藏来说高效开发关键在于科学管理,"低产气+高产水≠无法稳产"。通过对地质条件认识的深化、通过钻井和压裂等工程工艺的改进,通过开发思路的优化调整,同样可以在高含水致密气藏中做到气井的长期稳产。
Horizontal wells put into production in 2014 of Daniudi Gasfield show stable well productivity up to now, the law of productivity decline of these wells are apparently different from both wells in past years and wells in similar gas reservoirs.Causal analysis was carried out to study the stable production of horizon- tal wells put into production in 2014 of Daniudi Gasfield.Causes of the stable production were classified into geological reasons, engineering reasons and management reasons.Geological reasons include water produc- tion,length of sandstone in horizontal well and hydrocarbon-generating intensity.Engineering reasons refer mainly to design and construction of fracture and management reasons include the change of thought in drainage and proportion of production.Results show that water production is critical to the well production in tight gas reservoir, the lower the water production is, the easier the stable gas production will achieve. Bigger length of sandstone in horizontal well, higher hydrocarbon-generating intensity, bigger scale of frac- turing and higher flow-back rate would also be advantageous to stable gas production.For high water satu- ration tight gas reservoir,top priority should be given to drainage.It is important to clear the development idea that ＂drainage and gas production are equally important and should be carried out simultaneously＂.Re- duce the proportion of production under efficient drainage can reduce the pressure drop rate of formation and is in favor of stable gas production. It is also proposed that for tight gas reservoir, scientific manage- ment is the key to efficient development,＂ow gas production ＋ high water production：~productivity de- cline＂. Long-term stable production can also be achieved in high water saturation tight gas reservoir through deepened understanding of geological conditions, improvement of drilling/fracturing technology and optimization of development ideas.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2017年第1期127-134,共8页
Natural Gas Geoscience
基金
国家科技重大专项"鄂尔多斯盆地北缘低丰度致密低渗气藏开发关键技术"(编号:2016ZX05048-002)资助
关键词
致密气藏
高含水
水平井
稳产
产能递减
Tight gas reservoir
High water saturation
Horizontal well
Stable production
Productivity decline
