石油与天然气地质
石油與天然氣地質
석유여천연기지질
OIL & GAS GEOLOGY
2014年
1期
138-142
,共5页
刘波涛%李清泉%张福祥%王新海%李国亮%卢冲%岳海玲%王钊
劉波濤%李清泉%張福祥%王新海%李國亮%盧遲%嶽海玲%王釗
류파도%리청천%장복상%왕신해%리국량%로충%악해령%왕쇠
启动压力梯度%双孔介质%多级压裂%水平裂缝%产能分析%致密油藏
啟動壓力梯度%雙孔介質%多級壓裂%水平裂縫%產能分析%緻密油藏
계동압력제도%쌍공개질%다급압렬%수평렬봉%산능분석%치밀유장
starting pressure gradient%double porosity media%multistage fractured%horizontal fracture%productivity analy-sis%tight oil reservoir
新疆准噶尔盆地克拉玛依油田吉木萨尔( JMSE)凹陷二叠系芦草沟组( P2 l)是致密油储层主要层位。为提高单井产能,目前多采用多级分段压裂技术。以往对于水力压裂的研究多集中于压裂缝为垂直裂缝的情况,但目前已认识的垂直裂缝模型不能解释该区块实际资料,且通过理论及实验研究表明,由于天然裂缝方位与地应力的匹配关系,该区块在实际压裂过程中易产生水平裂缝。因此,目前的研究导致该储层在实施压裂生产而形成水平裂缝时缺乏理论指导。文中基于质量守恒定律,在同时考虑启动压力梯度、压力敏感性及有限导流压裂缝的情况下,建立了双孔单渗油藏中多级压裂水平裂缝井的无因次数学模型,采用隐式差分法和共轭梯度算法对无因次模型进行求解。通过数值模拟的方法依次研究了启动压力梯度、地层非均质系数、窜流系数、压力敏感系数、压裂缝导流能力、压裂缝条数对不稳态产能的影响。研究结果表明,裂缝参数及地层参数均对产能曲线有影响,故而在优选该类油藏的压裂方案时不仅要考虑裂缝参数,还要考虑到在地层压力降落时地层参数所带来的影响。
新疆準噶爾盆地剋拉瑪依油田吉木薩爾( JMSE)凹陷二疊繫蘆草溝組( P2 l)是緻密油儲層主要層位。為提高單井產能,目前多採用多級分段壓裂技術。以往對于水力壓裂的研究多集中于壓裂縫為垂直裂縫的情況,但目前已認識的垂直裂縫模型不能解釋該區塊實際資料,且通過理論及實驗研究錶明,由于天然裂縫方位與地應力的匹配關繫,該區塊在實際壓裂過程中易產生水平裂縫。因此,目前的研究導緻該儲層在實施壓裂生產而形成水平裂縫時缺乏理論指導。文中基于質量守恆定律,在同時攷慮啟動壓力梯度、壓力敏感性及有限導流壓裂縫的情況下,建立瞭雙孔單滲油藏中多級壓裂水平裂縫井的無因次數學模型,採用隱式差分法和共軛梯度算法對無因次模型進行求解。通過數值模擬的方法依次研究瞭啟動壓力梯度、地層非均質繫數、竄流繫數、壓力敏感繫數、壓裂縫導流能力、壓裂縫條數對不穩態產能的影響。研究結果錶明,裂縫參數及地層參數均對產能麯線有影響,故而在優選該類油藏的壓裂方案時不僅要攷慮裂縫參數,還要攷慮到在地層壓力降落時地層參數所帶來的影響。
신강준갈이분지극랍마의유전길목살이( JMSE)요함이첩계호초구조( P2 l)시치밀유저층주요층위。위제고단정산능,목전다채용다급분단압렬기술。이왕대우수력압렬적연구다집중우압렬봉위수직렬봉적정황,단목전이인식적수직렬봉모형불능해석해구괴실제자료,차통과이론급실험연구표명,유우천연렬봉방위여지응력적필배관계,해구괴재실제압렬과정중역산생수평렬봉。인차,목전적연구도치해저층재실시압렬생산이형성수평렬봉시결핍이론지도。문중기우질량수항정률,재동시고필계동압력제도、압력민감성급유한도류압렬봉적정황하,건립료쌍공단삼유장중다급압렬수평렬봉정적무인차수학모형,채용은식차분법화공액제도산법대무인차모형진행구해。통과수치모의적방법의차연구료계동압력제도、지층비균질계수、찬류계수、압력민감계수、압렬봉도류능력、압렬봉조수대불은태산능적영향。연구결과표명,렬봉삼수급지층삼수균대산능곡선유영향,고이재우선해류유장적압렬방안시불부요고필렬봉삼수,환요고필도재지층압력강락시지층삼수소대래적영향。
Permian Lucaogou Formation ( P2 l ) in Jimusaer ( JMSE ) sag of Karamay oilfield is a typical representative of tight oil reservoirs in Junggar Basin .Staged fracturing technology is commonly used to improve the productivity of single well .While previous researches were more concentrated on the cases of vertical fractures ,the vertical fracture model could not explain the actual data in the blocks .At the same time,the theoretical and experimental studies show that horizontal cracks are easy to form during the process of fracturing according to the matching relationship between natural fracture azimuth and geostress .Therefore there is a lack of theoretical guidance in study area .Based on the law of conservation of mass and considerations of starting pressure gradient ,pressure sensitivity and finite conductivity fractures ,a dimensionless mathematical model has been set up to study the flow in the multistage horizontal fracturing fractured well in dual porosity and single permeability reservoir in this paper .And numerical solutions of the model are obtained by using implicit diffe-rence method and conjugate gradient algorithms .The effects on unsteady productivity of starting pressure gradient ,forma-tion heterogeneity coefficient ,interporosity flow coefficient ,pressure sensitive coefficient ,conductivity and the number of cracks are studied through numerical simulation in turn .Research results show that the fracture parameters and formation parameters affect the productivity curves .So it is necessary to consider both fracture parameters and the pressure decline reasonably ,as choosing an appropriate fracturing scheme to obtain maximum productivity .