摘要
煤层气藏具有低渗透率特点,这使得其在直井排采前须对产层进行压裂改造,而压裂裂缝参数对井距的确定影响很大,因此研究裂缝长度、导流能力与井距的关系具有实际意义。通过对比不同裂缝穿透比和导流能力下的煤层气产量与采出程度,探讨裂缝参数对煤层气产出的影响规律;并以煤层气开采15 a采出程度达到50%时的井距作为评价指标,研究压裂效果与井距的关系。研究结果表明,裂缝越长,导流能力越大,井距就越大—尤其在渗透率较小时,裂缝参数对井距的影响更明显。因此,在确定煤层气藏井距时,由于人工裂缝影响,裂缝方向的井距可适当放大。以我国韩城矿区煤层气区块储层参数为例,在给定优化指标下,宜选择矩形井网(350 m×300 m),或菱形井网(对角线长度为700 m×400 m)。
Hydraulic fracturing is usually necessary in low permeability area for vertical CBM well,this means the well spacing is dependent on the fracture parameter.By comparing the production and recovery in different fracture length and conductivity,the effect of fracture on gas production is analyzed and the law is revealed.Based on evaluation of the well spacing in which the gas recovery is up to 50% for 15 years,the relation of fracture and well spacing is studied.It shows that the well spacing can be enlarged as the length and conductivity of fracture become larger,especially in low permeability coal seam.Thus,the well spacing along fracture direction can be increased,rectangular or diamond patterns are good choice.Take a CBM reservoir in China for example,rectangular pattern 350 m×300 m or diamond pattern 700 m×400 m are recommended.
出处
《煤田地质与勘探》
CAS
CSCD
北大核心
2011年第4期16-19,共4页
Coal Geology & Exploration
基金
国家重大基础研究发展计划(973计划)项目(2009CB219606)
国家科技重大专项课题(2009ZX05038-005)
关键词
煤层气
裂缝长度
裂缝导流能力
井距
井网
coalbed methane（CBM）
fracture length
fracture conductivity
well spacing
well pattern
