煤层气井水力压裂设计

1、32江汉石油学院学报2001年6月第23卷第2期Journal of J i anghan Petroleu m I n stitute Jun 12001V o l 123N o 12煤层气井水力压裂设计张志全, 张军许弟龙, 胡东张保国, 唐艳(江汉石油学院石油工程系, 湖北荆州434102 (胜利油田分公司孤岛采油厂, 山东东营257000 (中原油田分公司, 河南濮阳457001摘要针对煤层气井储层特性和压裂的特殊性, 选择了拟三维模型进行水力压裂设计。针对一口具体井的资料进行了模拟计算, 计算结果合理。同时就地面注液排量、压裂液稠度系数和地应力差值对裂缝几何形态的影响进行了计算和分析

2、, 并提出了相应的建议。关键词煤层气井; 水力压裂; 设计; 模型; 效果中图分类号T E 35711; T E 13212文献标识码A 文章编号10009752(2001 02003202煤层气是一种非常规天然气资源。煤层气储层与常规天然气储层相比具有很大的差异1。煤层通常以多个煤层组形式存在, 各组之间相距的距离不等, 这一特征加上煤岩本身的一些特性, 使得煤层压裂与常规储层压裂之间存在一些差异1。一般情况下, , 。其副作用主要表现在:限制裂缝延伸; 降低压裂效率; ; 煤层中压裂裂缝的生成与扩张, , 它们同时, , 通常(非煤层气 25进行煤层气井水力压裂设计。11 基本假设裂缝为垂

3、直裂缝, 以井筒为轴心对称分布, 裂缝剖面近似为椭圆; 生产层与遮挡层的地应力均匀分布, 且上下遮挡层的地应力相等; 流体沿缝长方向一维流动; 油层岩石为理想的线弹性断裂体, 裂缝在垂直平面内符合平面应变条件。2 模型的建立连续性方程Q t =V f (t +V l (t 。式中, Q 为地面泵注排量,m 3 m in; t 为注液时间, m in; V f (t 为注液t 时的裂缝体积,m 3; V l (t 为注液t 时压裂液滤失体积, m 3。缝中流体流动压降方程nn =-n 2n +1d x 3n h (x W 0(x 式中, W 0(x 为缝中x 处的最大缝宽,m ; h (x 为缝

4、中x 处的高度, m ; K 为压裂液的稠度系数, kPa s n ; n 为压裂液的流态指数, 无因次; q (x 为缝中x 处的液体流量,m 3 m in; P 为压裂液流动所具有的压力, kPa 。裂缝宽度方程W (x , =P (x l (x 1-2-1-2arcco s f 1-G P (x f 1ln22122+ln222f - f -21。收稿日期20000226作者简介张志全(1965 , 男, 1987年大学毕业, 硕士, 讲师, 现主要从事采油工程的教学与研究。第23卷第2期张志全等:煤层气井水力压裂设计33式中, 为缝中x 处的无因次高度; l (x 为缝内x 处的半缝高

5、,m ; G 为岩石的剪切弹性模量, kPa; 为岩石的泊松比, 无因次; S 为生产层与遮挡层的地应力差, kPa; P (x 为缝中x 处的净压力, kPa; f 1为缝中x 处的无因次厚度。裂缝高度方程=d x-hn -1(x nnq (x (x W 2n +102h (x -211-f式中, K I C 为断裂韧性的极限值, kPa m 015。2计算实例及分析利用编制的程序对一口煤层气井在压裂过程中裂缝延伸表1地面注液排量对裂缝几何形态的影响的动态几何尺寸进行了模拟计算。其结果为:井筒最大缝宽注液排量裂缝长度裂缝宽度裂缝半高度3-1m m m m in 010459m ; 裂缝一翼缝

6、长155195m ; 井筒最大缝高4102251390601011851525114197m 。同时, 研究了裂缝几何形态的影响因素。415242118750101195186161地面注液排量对裂缝几何形态的影响随注液排量的510257181250120612190增加, 裂缝的长度、宽度和高度均随之增加, 但裂缝的长度和高度增加较快(表1 。2 情况下, 随稠度系数的增加, 3 增加, 加(表3 。表2稠度系数对裂缝几何形态的影响稠度系数7100712571507175810081258150817591009125-7n5156106157107581081527211113231867

7、23351332034613672000012001010121010121010122010122615581618810711895714857717705810454813112表3地应力对裂缝几何形态的影响地应力差201910920461292073169210113021291132157117218514222131902242159裂缝长度31119141311191413111914131119141311191413111914131119141311191413111914131119141裂缝宽度01012101012101012101012101012101012101

8、0121010121010121010121裂缝半高度714381714440714497714557714617714677714737714797714857714917裂缝长度318188673171460931610547314166803131281231119141310156643091238330719297裂缝宽度010110010112010114010117010119010121010123010126010128裂缝半高度810553719378718226717095715985714895713826712777711749大多数煤层气藏投产前, 水力压裂是一项必

9、须进行的增产措施。在进行煤层气井的水力压裂设计时,要先进行地层评价, 优选设计模型及参数, 以获得较好的经济效益。参考文献1赵庆波, 刘兵, 姚超1世界煤层气工业发展现状M 1北京:地质出版社, 199812Jeffrey R G , W o ld M B , Cho i S K , et a l 1Sti m ulati on fo r m ethane gas recovery from coal J 1SPE P roducti on &Facilities , 1998, 13(3 :20020713万人傅, 罗英俊1采油技术手册(修订本 (第九分册 M 1北京:石油工业出版社

10、, 199814王晓泉, 陈作, 姚飞1水力压裂技术现状及发展展望J 1钻采工艺, 1998, 21(2 :283215江汉石油学院“石油工程专业改革与建设”项目组1石油工程设计M 1北京:石油工业出版社, 19991编辑弘文 JOURNAL O F J I A NGHAN PETROLEU M I N S TI TUTEJ un 12001Abstract :A n early evaluati on is m ade in com b inati on w ith o ther static data , such as logging , co ringand w ell logging

11、 by u sing the analysis resu lts of p ressu re bu ildup , vertical in terference and p roductivity testings in T azhong 4o ilfield 1T he resu lt of evaluati on show s that in the o ilfield the physical p rop erties of reservo irs w ith in the sam e group are si m ilar , bu t there ex ists b igger di

12、fference betw een group s 1A n obvi ou s boundary respon se ex ists in group C , in w h ich lateral con tinu ity is poo r and distribu ti on range is li m ited 1T here is a b ig variati on of reservo ir physical p roperties in group C , in group C there ex ist boundary respon ses from som e of the r

13、eservo irs , the m ain respon ses include that w ith in the detecti on range the p roperty of hom ogeneou s fo r m ati on is infin ite , reservo ir physical p roperty is good , its th ickness is b ig , distribu ti on range is w ide , p roductivity is h igh enough and in the reservo ir vertical perco

14、 lati on character is obvi ou s 1It is p ropo sed that ho rizon tal w ell w ou ld be cho sen to i m p rove the efficiency of o ilfield developm en t 1Key words :fo r m ati on testing ; test data ; evaluati on ; T ari m B asin26Re ma i n i ng O il D istr ibution and Its Poten ti a l Production of Es

15、2Reservo ir i n H igh W a ter -cut Stage i n Pucheng O ilf ieldWUB ranch Co mp any S IN O P EC , P uy ang 457001J i 2cha n , CHEN Gua ng 2m ing , L I U Guo 2hong , ZHOU D a o 2qua n , J I N G X in 2rong , MO Ying 2ke (Z hongy uan O ilf ieldAbstract :E s 2reservo ir is a com p licated fau lt b lock o

16、 il reservo ir 1A fter en tering in to the h igh w ater 2cu t stage , o il p roducti on decreases , and w ater 2cu t increases rap idly , thu s adap tab ility is poo r in in jecti on 2p roducti on system 1B y u sing the w ell logging data , analyzing the reservo ir p lane heterogeneity and sedi m en

17、 tary facies , num erical si m u lati on as w ell as logging 2sedi m en tary m icrofacies , a study is carried ou t on the ru les and m ethods of rem ain ing o il distribu ti on 1A fter the sti m u lati on of po ten tial p roducti on is i m p lem en ted , o il p roducti on enhancem en t is obvi ou s

18、 1T he resu lt dem on strates that it cou ld be u sed fo r the developm en t of si m ilar o il reservo irs 1Key words :h igh w ater 2cu t stage ; rem ain ing o il distribu ti ; rem on ; po ten tial p roducti on ; Pucheng o ilfield29Nu m er ica l Si m ula tion for Produc i ng V I Usi ng Hor izon ta l

19、 Fracture -a ssisted Steam f lood i L I N G J ia n 2jun , L I J i 2, 2bo , n J han P etroleum Institu te , J ing z hou 434102 FANG Tie 2, I Fa 2Z hongy uan O ilf ield B ranch Co mp any S IN O P EC , P uy ang 457001 of s o reservo irs w ith low per m eab ility and litho logic in terbeds (single lti p

20、 p roducti on efficiency from ho rizon tal fractu re 2assisted steam flooding are studied w erical si m u lati on 1T he resu lts show that in terbed in the viscou s o il reservo r is an undefined variab le du ring the reservo ir p roducti on 1T he differen t fractu ring open ing in steam in jecti on

21、 w ell has differen t effects on the reservo ir w ith in terbeds , the degree of fractu ring open ing in the steam in jecti on w ell is defined by the typ es and distribu ti on of in terbeds 1Key words :viscou s o il reservo ir ; fractu ring fractu re ; steam flooding ; litho logic in terbed ; steam

22、 2o il rati o ; num erical si m u lati on32Hydraul ic Fractur i ng D esign of Coa l -bed Ga sW ellZHANG Zh i 2qua n , ZHANG J un (J iang han P etroleum Institu te , J ing z hou 434102XU D i 2long , HU D ong (S heng li O ilf ield B ranch Co mp any , S IN O P EC , D ongy ing 257000ZHANG B a o 2guo , T

23、 ANG Ya n (Z hongy uan O ilf ield B ranch Co mp any , S IN O P EC , P uy ang 457001Abstract :In con siderati on of reservo ir charateristics and p articalarity of fractu ring of coal 2bed gas w ell , a p suedo 3D fractu re m odel is selected to design the hydrau lic fractu ring 1A si m u lati on cal

24、cu lati on is perfo r m ed w ith data from a specific w ell , of w h ich the resu lt is reasonab le , at the sam e ti m e calcu lati on and analysis are conducted on the geom etry of fractu res based on the disp lacem en t of su rface in jected flu id , den sity coefficien t of fractu ring flu id an

25、d differen tial value of earth stress , thu s related p ropo sals are m ade 1Key words :coal 2bed gas w ell ; hydrau lic fractu ring ; design ; m odel ; efficiency MAX ia ng 2fe ng , L I X ia o 2q i , ZANG Hong 2he , ZHANG Ga i 2z h i , WANG P a i 2y ing (Z hongy uan O ilf ield B ranch Co mp any ,34Flu id A ssisted L if ti ng Techn ique i n O il Pu m p i ng W ell of H