表2 定向造斜钻具组合造斜率
钻具组合
单弯度数
/( )
滑动钻进造斜率
/( ) (30m)-1
复合钻进造斜率
/( ) (30m)-1组合(1)1 3.86~5.191~1.5
组合(1) 1.25 4.61~6.911~1.5
组合(2)1 3.22~4.84-0.25~0.5
组合(2) 1.25 4.11~6.16-0.25~0.5 一般当设计井斜在15 内时,选用组合(2),直接造斜到稳斜角后进行复合钻进稳斜,起钻前调整好方位。当设计井斜大于15 时,采用组合(1),当造斜到一定角度(以该角度稳斜钻进能钻达目标下靶边)后,实施复合钻进增斜,起钻前调整好方位。为顺利快速完成定向造斜,采取了以下措施。
(1)定向造斜一般使用有线随钻或无线随钻监测井眼轨迹。井斜角 小于5 时,采用磁性工具面; 大于5 时,采用重力高边。
(2)钻头型号。造斜井段常使用高效HJ517三牙轮钻头,以适应单弯螺杆的高转速及复合钻进的需要;另外对应用PDC钻头进行定向造斜,进行了试验,效果良好。虽然PDC钻头钻进扭矩大,对钻压极为敏感,反扭角变化大,工具面难以控制,但使用随钻测斜仪监测工具面,送钻方法得当是可以解决此问题的。
(3)优选钻压。采用试钻法,确定最优钻压值,使机械钻速达到较高值。一般滑动钻进时使泵压比螺杆悬空泵压升高1~ 1.5MPa,复合钻进时,升高0.5MPa时,此时机械钻速普遍较高。
(4)送钻要均匀。防止反扭角波动过大而影响
23
董云安等:小位移深造斜点定向井施工技术
造斜效果,特别是用PDC钻头钻进时。
3.3 稳斜段轨迹控制
稳斜段一般使用2种钻具组合,组合(1)为常规微增钻具组合: 216mm3A钻头+ 214mm STB+ 159mm NDC 1根+ 214mm STB+ 159mm DC 1根+ 214mm STB+ 159mm DC 2柱+ 127mm加重钻杆 10柱+ 127mm DP。组合(2)为常规稳斜钻具组合: 216m m3A钻头+ 214mm STB+ 159mm DC 2m+ 214mm STB+ 159mm NDC 1根+ 214mm STB+ 159m m DC 2根+ 214mm STB+ 159mm DC 2柱+ 127mm加重钻杆 10柱+ 127mm DP。钻进参数:钻压180kN;转速60r/min;排量30L/s;泵压17MPa。
根据轨迹预测结果,如需2( )/100m的增斜率钻进才能中靶或稳斜井段为易降斜地层(如Ef4地层)时,则选用组合(1);如能稳斜中靶,则选用组合
(2)钻进。
3.4 降斜段轨迹控制
降斜段采用常规钟摆钻具组合。施工时,一般视轨迹控制情况,先以50kN钻压钻进20m,再以120 ~140kN钻压钻进。钻进过程中,使用单点测斜仪器监测井眼轨迹,视测斜情况,及时调整钻井参数或钻具组合,必要时上动力钻具降斜。
3.5 调整方位
虽然小位移深造斜点定向井能有效避免扭方位,但钻遇某些方位漂移异常的地层时,则扭一次方位也是难以避免的。钻具组合一般选用造斜钻具组合(2),扭方位成功后,实施复合钻进,以充分使用好钻头。调整方位时,要求将方位扭到靶心,可避免二次扭方位。
4 典型实例
Z22-3井为1口单目标、小靶区定向井,靶区半径为20m,其它数据见表1。设计剖面为直 增 稳三段制。直井段使用双扶正器刚性钟摆钻具,二开后1只 216mm HA437钻头钻进至1381.04m,机械钻速为20.02m/h。再以1只FM282C型PDC钻头钻达造斜点2588.13m。直井段钻进时,使用单点测斜仪监测井眼轨迹,起钻前测多点。经计算,直井段底部井眼参数为:井深2571.83m时,井斜角为2.2 ,方位角为73.41 ,垂直井深为2571.39m,累计E轴分量为30.24m,累计N轴分量为- 3.27m,闭合位移为30.42m,闭合方位为96.10 。使用定向井设计软件做好待钻井段设计,调整井身剖面设计如下:井底至靶心方位角为284.73 ,井底至靶心位移为117.43m,以15( )/100m的造斜率直接造斜到19.06 后稳斜钻进中靶。考虑邻井下部地层有减方位趋势,确定初始造斜方位角为288 。在井深2588.13m,下入定向造斜组合(1),钻头为 216mmHJ517,定向滑动造斜到2700.40m,此时井斜为19.5 ,方位为287.84 。考虑到下部地层为易降斜地层,采用微增钻具进行稳斜钻进,至井深3085m而完钻,稳斜效果较好。全井中途未扭方位,靶心距为12.03m,全井机械钻速为9.04m/h,钻井周期为23d2h,事故时效及复杂时效均为0,仅6趟起下钻钻完井深。
5 几点认识
(1)实践证明,应用小位移深造斜点定向井技术是降低定向井扭方位及更换钻具组合次数,降低定向井成本的一种有效办法。
(2)随钻测量技术与单弯螺杆钻进技术是开展小位移深造斜点定向井施工的技术保证。
(3)直井段的防斜打直是充分发挥小位移深造斜点定向井优点的关键。
(4)小位移深造斜点定向井剖面设计时,应采用适当高的造斜率,尽量下移造斜点,减少斜井段长度,以有效减少扭方位及更换钻具组合的次数。
(5)定井位时,对单靶定向井,井斜小于25 的双靶定向井及双靶挂直定向井,在地面条件及防碰绕障允许的情况下,尽可能定小位移深造斜点定向井,以降低定向井的施工成本。
参 考 文 献
[1] 周继坤.单弯滑动导向钻井的几个重要问题.石油钻探
技术,2002,30(4):25~27
[2] 张东海.濮城油田定向井综合钻井技术的应用.钻采工
艺,1997,20(2):15~17
[3] 董来明,陈小元,冯俊.导向钻具组合在江苏油田的应
用.石油钻采工艺,2001,23(3):13~15
(收稿日期 2002 11 20)
编辑 张振清
24石油钻采工艺 2003年2月(第25卷)第1期
OIL DRILLING&PRODUCTIO N TECHNOLOGY
Vol.25 No.1 Feb.2003
ABSTRACT
ROTARY C LOSED LOOP STEERABLE DRILLING SYS TEM
by Yang Jianfeng,Zhang Shaohuai(Steering Drilling Inst., Xi an Petroleum Inst.)
Abstract Rotary closed loop drilli ng technology is one of the hi techs of today s drilling industry,and it represents the direction of drilling technology in the future.The typical structures and char acteristics of rotary closed loop drilling systems at home and aboard,together with their integrating methods,downhole direc ti onal con trolling units,and surface moni tori ng systems are de scribed.The rotary steerable drilling tools have many advantages, such as continuous3D steering,extending reach i n length,i mprov ing drilling speed,shortening completion ti me,and cutti ng down drilling cost,etc.A rotary steerable closed loop drilling system MRSS developed by Steering Drilling Insti tute is presented,focuses on its direction controlling principle,five parts of composi tions, and main technical features.It stresses on the importance of devel oping and integrating drilli ng informati on and planning software.
Key words directional drilling rotary closed loop drillin g steering tool communication system monitoring system GENERAL COND ITION A ND TECHNICAL D IFFICULTIES OF EXTENDED REACH D RILLING AND ITS REQUIRE MENTS ON TOOLS AND INSTRUMENT
by Su Yi nao,Dou Xiurong(Exploration and Development Research Inst.,PetroChina)
Abstract As a newly developed comprehensive high tech drilling technology,extended reach drilling technology can effec ti vely enhance oil recovery,however,this technology is technically difficult and has higher requirements on drilling tools and instru men ts.Its definition,uses,development,technical specifications and results,economic benefits and prospects are presen ted;based on which,the basic features of extended reach drilling,its techni cal difficulties and requirements on downhole tools and instruments are further illustrated.
Key words extended reach well drilling technology drilling tool instru ment review
DR ILLING TEC HNOLOGY FOR TZ406DOUBLE STAGE HORIZONTAL WELL
by Hu Pinggong(No.2Drilling Co.of Huabei Petroleum Ad mini stration Bureau)
Abstract The aim of drilling exploratory well TZ406is to ascertain the oil bearing structures and develop the thin oil reser voirs economically.A pilot hole was drilled to verify the oil and gas reserves and locate their exact positions,and the hole was then backfilled;after backfilling,a double stage horizontal well was drilled to develop the two thin oil reservoirs at di fferent depths usin g one hole.During the whole drillin g process,only502m long of surface casing was run in hole without intermediate casing run in, and the open hole was as long as3628.83m.MWD tools were used,and by using of reversed BHA and op timizing of d r illing pa rameters,precise target hitting was achieved.The horizontal well was successfully drilled,with a measured depth of4131m,a TVD of3686.83m,well inclination of89.98 ,orientation of48.72 and horizontal displacement of538.26m.An initial production rate of86t per day was obtained after the well was pu t into production.
Key words double stage horizon tal well pilot hole side tracking combinati on d r illing reversed drilling tool
SHORT RADIUS HORIZONTAL SIDETRACKING TECH NOLOGY IN TAHE OILFIELD
by Wang Xin,Wan Jiaoyu,et al(Directional Well Co.of Drilli ng Tech.Research Inst.,Xinjiang Petroleum Administration B ureau)
Abstract The KOP in the short radius sidetracking horizon tal well in T ahe Oil field is usually located below5300m,this makes horizontal drilling very difficul t.By illustrating the technical diffi culties of drilling short radius sidetracking horizontal well,combin ing with the design and field drilling of well TK405C H,the suc cessful practices on downhole tool and instru ment modification, suitable techniques and technologies selection were presented.T he following technical difficulties such as trajectory control technology, mechanics analysis and friction/torque analysis of drill pipe in hi gh building rate in the short radius horizon tal well were also discussed, and some corresponding solutions were p roposed,which were field p roven effective.
