1、連續(xù)油管側(cè)鉆工藝技術(shù)連續(xù)油管作業(yè)技術(shù)現(xiàn)已成為世界油氣工業(yè)技術(shù)研究與應(yīng)用中的一個熱點。世界上現(xiàn)有連續(xù)油管作業(yè)機的數(shù)量已達1000多臺，連續(xù)油管的年耗量近500萬m，連續(xù)油管最大作業(yè)井深已超過9000m。國外連續(xù)油管作業(yè)技術(shù)已能對陸地和海上油氣井進行20多種作業(yè)。利用連續(xù)油管修井已代表著當今世界修井技術(shù)的發(fā)展方向，并將作為一種常規(guī)、高效的作業(yè)技術(shù)在世界范圍內(nèi)普及。近年來連續(xù)油管鉆井技術(shù)亦成為世界鉆井技術(shù)的熱點。目前連續(xù)油管的最大鉆井深度已超過6900m。現(xiàn)在連續(xù)油管外徑也由原來的12.7mm發(fā)展到114.3mm。連續(xù)油管鉆井(CTD)是20世紀90年代國外發(fā)展起來的熱門技術(shù)，特別是隨著相關(guān)技術(shù)的研

2、究和改進，其應(yīng)用向縱橫兩方面擴展，越來越廣泛，已經(jīng)擴展到石油行業(yè)上游各個領(lǐng)域。除了常規(guī)管道集輸、生產(chǎn)油管以及修井作業(yè)外，幾乎涵蓋了油氣井完井、測井、增注、老井重鉆、加深、側(cè)鉆以及小井眼、欠平衡、過平衡和水平井鉆井等20多種作業(yè)項目，并顯示出良好的發(fā)展前景。由于連續(xù)油管鉆井廣泛的適應(yīng)性，鉆井的高效、快速，突出的低成本優(yōu)勢，以及對環(huán)境的低污染等特點，將成為石油鉆井技術(shù)發(fā)展的重要方向。連續(xù)油管鉆井有可能成為鉆井未來的主流，最終引發(fā)石油工業(yè)的一場革命。近年來，世界上用連續(xù)油管所鉆井的數(shù)量急劇增加，1996年為410口，1997年猛增至600多口，目前仍在繼續(xù)增加。近年來，隨著連續(xù)油管器材和制造工藝的進

3、一步發(fā)展，可靠性高的高強度大直徑連續(xù)油管、小直徑容積式馬達、先進的定向工具及測量系統(tǒng)和金剛石鉆頭的相繼問世，極大地推動了連續(xù)油管鉆井術(shù)應(yīng)用及發(fā)展。在鉆井工程中，連續(xù)油管應(yīng)用包括：取心、安放造斜器和開窗側(cè)鉆、無線隨鉆測量、導向工具的有線測量、下尾管和懸掛器等。連續(xù)油管鉆井與常規(guī)鉆井相比，主要具備以下幾方面的優(yōu)勢： 能夠安全地實現(xiàn)欠平衡壓力鉆井作業(yè)，有利于保護油氣層，提高鉆速。由于連續(xù)油管沒有接頭，為實現(xiàn)欠平衡壓力鉆井創(chuàng)造了有利條件。安裝在防噴器上方的環(huán)形橡膠，其作用相當于始終處于關(guān)閉狀態(tài)的環(huán)形防噴器，它能在鉆進和起下鉆作業(yè)過程中密封環(huán)空，從而使鉆井作業(yè)得以在欠平衡壓力下進行，由此可防止地層遭到傷

4、害并大大提高鉆速。 連續(xù)油管鉆井特別適用于小眼井鉆井、老井側(cè)鉆、老井加深。在老井側(cè)鉆或加深作業(yè)中，因連續(xù)油管直徑小可進行過油管作業(yè)，無需取出老井中現(xiàn)有的生產(chǎn)設(shè)備，從而實現(xiàn)邊采邊鉆的目的，可顯著節(jié)約鉆井成本。 連續(xù)油管鉆井特別適用于小眼井鉆井、老井側(cè)鉆、老井加深。在老井側(cè)鉆或加深作業(yè)中，因連續(xù)油管直徑小可進行過油管作業(yè)，無需取出老井中現(xiàn)有的生產(chǎn)設(shè)備，從而實現(xiàn)邊采邊鉆的目的，可顯著節(jié)約鉆井成本。 地面設(shè)備少，占地面積小，特別適合于條件受限制的地面或海上平臺作業(yè)，減少對周圍環(huán)境的影響，降低井場建設(shè)和維護費用，同時設(shè)備移運安裝快捷、方便、靈活。 連續(xù)油管內(nèi)可以內(nèi)置電纜，有利于實現(xiàn)自動控制和隨鉆測量。

5、減少施工隊伍的作業(yè)人員。 貝克休斯連續(xù)油管鉆井技術(shù)發(fā)展歷程In 1991 Baker Hughes INTEQ started the Research & Development and field trials of the worlds first E-line CT drilling prototype BHA system, OrientXPress (OXP). Over the years INTEQ developed the industry standard for CT drilling and gained valuable experience in major wo

6、rldwide re-entry drilling projects in underbalanced and overbalanced drilling mode.The following are a few of INTEQs Coiled Tubing Drilling milestones: 1992 First pilot series run in Germany to verify concept of CT orienting tool 1995 OrientXPress successfully drilled well at 265 in Holland 1998 Dev

7、elopment of US MPR for CT Drilling Technically and economically most successful CT drilled well; Drilled 890m in 8 days (22m/h) Drilled over 19,500m of well bore on Coiled Tubing 1999 Successfully ran worlds first commercial Ultra Slim LWD geosteering job (US MPR) First 3” open hole side track on Co

8、iled Tubing 60 wells drilled (Underbalanced: 36) with OrientXPress World record longest horizontal section drilled with CT in Oman - 1425 m. 2001 Initial field tests of worlds first E-line operated 2-3/8” CoilTrak Record run on CT (525 m/Day) with OrientXPress in Alaska. 2002 Market introduction of

9、the 2-3/8” CoilTrak and 2-3/8” X-treme motors. First field tests of E-line operated 3” CoilTrak BHA 2003 Market introduction of the 3” CoilTrak in UB two-phase flow and 150 temperature. 貝克休斯第一代連續(xù)油管鉆具組合 貝克休斯第二代連續(xù)油管鉆具組合 貝克休斯第二代連續(xù)油管鉆具組合 貝克休斯第二代連續(xù)油管鉆具組合 Project Name Microhole Coiled Tubing Bottom Hole A

10、ssemblies Project Objectives Develop a 2-3/8” Rib Steering Motor device (RSM) Develop a 2-3/8” Resistivity measurement device (MPR) Manufacture 2 prototypes of each Laboratory & Field Test with a CoilTrak bottom hole assembly Project Duration 18 months (extended to 21 months) Start Date: 1 October，

11、2004 Start Date: 1 October， 2004 End Date: 31 March， 2006 (extended to June 30， 2006) 貝克休斯連續(xù)油管鉆井研發(fā)項目概述Multiple Propagation Resistivity (MPR) moduleThe tool consists of the following sections: Upper Adapter Sub Mechanical and Electrical uphole connection to existing 2-3/8” CoilTrak System Electronics

12、 Housin -houses transmitter and receiver electronics along with an integrated power supply and modem. Upper and LowerTransmitter Antennas Two Receiver Antennas Lower Adapter Sub Mechanical and Electrical downhole connection to existing 2-3/8” CoilTrak System 貝克休斯小井眼電阻率短節(jié) 貝克休斯小井眼電阻率短節(jié) 貝克休斯小井眼電阻率短節(jié)Ele

13、ctrical Description, 2-3/8” MPRThe MPR electronics consists of two printed circuit board assemblies (PCBA), a transmitter PCBA and a receiver PCBA. Due to space limitations, the power supply and modem, which are usually on a separate PCBA, were integrated into the transmitter PCBA. This integration

14、made it necessary to take extra precautions to minimize noise interference with the receiver communication. Shown below is the actual transmitter PCBA. 貝克休斯小井眼電阻率短節(jié)Transmitter PCBA, 2-3/8 MPRThe transmitter portion of the PCBA consists of a separate circuit to drive each of the transmitter antennas.

15、 These circuits are capable of operating at 2MHz and 400 kHz. The transmitter sequentially receives two numerically controlled and phase locked signals from the receiver PCBA through a coax cable. Along with a command to turn on the transmitter circuits one at a time, this signal is sequentially amp

16、lified and sent to the appropriate antenna which emits the signal into the formation.The power supply on the transmitter PCBA supplies the necessary power to the amplifiers and the modem. The modem part of the transmitter PCBA communicates information via the correct protocol. 貝克休斯小井眼電阻率短節(jié)Receiver P

17、CBA, 2-3/8 MPRThe receiver PCBA, shown below, is electrically connected to the two receiver antennas.The signal received at each antenna is amplified, mixed with transmitting frequency and phase locked to output. This signal is further amplified, and passed through filters to produce clean measurabl

18、e analog signals. These analog signals are then digitized, passed through a buffer and sent to the Digital Signal Processor (DSP). The DSP compares transmitted and received signals. Since the received signals pass through the formation,they are attenuated in amplitude and phase. The DSP calculates t

19、hese changes and then stores and sends the information to the surface for further processing into resistivity values. 貝克休斯小井眼電阻率短節(jié)2 3/8 MPR - Mechanical DescriptionThe 2 3/8” MPR is composed of two sections: the antenna Sub and the electronics chassis. The tool contains two sections with reduced out

20、er diameter for improved flexibility and increased dogleg capability.The upper section of the tool contains the Electronics Chassis that houses the two printed circuit boards. The boards are shielded from the drilling fluid by an Inconel4 housing. Crossdrilled holes and long, gundrilled passages, co

21、nnect the boards to the antennas as well as to external tools in the drill string.Upper section：electronic frame and housing 貝克休斯小井眼電阻率短節(jié)The four antennas of the USMPR are separate components that house the ferrites and antenna wire. PEEK5 panels protect the ferrites from exposure to drilling fluids

22、. It would have been possible to machine the mechanical features of the antenna directly into the walls of the antenna sub.However, making the components separate parts isolates the stress concentrations associated with the ferrite pockets and screw holes thus extending the life of the more expensiv

23、e antenna sub. This feature makes the ferrites more accessible for assembly and maintenance.Antenna section 貝克休斯小井眼電阻率短節(jié)To protect against premature wear from contact with the borehole wall, the 2-3/8” MPR has two wear sleeves. These sacrificial parts have laser-clad hard facing to improve wear life

24、 and are replaceable.Each antenna on the tool has a machined pocket that contains the corresponding tuning circuit boards. These electronics are easily accessible via a removable hatch cover located adjacent to the related antenna. Internally drilled passages contain the wiring that electrically con

25、nects all components.Wear Sleevehatch cover 貝克休斯小井眼電阻率短節(jié) 貝克休斯小井眼電阻率短節(jié)The operation of the 2 3/8” MPR is the same as all the larger size MPR tools developed by Baker Hughes. The two transmitter antennas located outboard emit two constant frequency propagation signals at 2 MHz and 400 kHz. The signal

26、travels through the formation and is detected by the two receiver antennas located inboard. The tool measures the raw signal phase (velocity) and amplitude for each frequency from each transmitter to receiver combination. This is 16 measurements (8 for each frequency).From these measurements， the to

27、ol calculates compensated phase difference and attenuation from far to near receiver. Algorithms in the surface system software transform this compensated phase difference and attenuation into a resistivity value. 貝克休斯電阻率測量原理In a high resistivity (less conductive) formation， the signals travel at a

28、higher velocity with less attenuation. Contrary，in a low resistivity (more conductive) formation，the signals travel at a lower velocity with higher attenuation. Generally， the tool is more accurate in low resistivity formations due to a higher phase difference and amplitude ratio.Depth of investigat

29、ion(DOI) increases with increasing resistivity. The 400 kHz signal propagates further into the formation than the 2 MHz signal. In low resistivity formations， much of the signal is blocked from penetrating deep into the formation. This effect becomes worse with increasing conductivity of the drillin

30、g fluid. 貝克休斯電阻率測量原理 貝克休斯連續(xù)油管導向工具Rib-Steering Motor (RSM) ModuleThe RSM fits within the lowermost portion of the CTD-BHA, immediately above the bit. The object of the RSM is to deliver true closed-loop steering capability to the 2-3/8” CoilTrak BHA, thereby enabling the drilling of a low tortuosity

31、extended reach microhole.The RSM contains a Near Bit Inclination sensor located 6.89 feet above the base of the RSM, immediately above the motor section.The motor section is based on Baker Hughes INTEQs X-treme drilling motor, which can supply a high level of power and torque.Directional control dur

32、ing drilling is provided by a steering head, consisting of three hydraulicallyThe operation of the RSM is rather simple, at least conceptually. The steering ribs extend from the body of the tool to exert a force against the wall of the wellbore, which creates a bit side force in the desired directio

33、n. 貝克休斯連續(xù)油管導向工具the steering ribs of the 2-3/8” RSM are fully retracted, and extended by 8mm.Since an e-line connects the downhole hydraulic control unit with the surface control system, borehole trajectory comes under tight directional control with this system. This reduces borehole tortuosity (bore

34、hole tortuosity is an unpleasant fact when drilling with bent motors) which results in reduced borehole friction and extended reach microholes. 貝克休斯連續(xù)油管導向工具該新型BHA可提高CTD作業(yè)的適應(yīng)性，采用套管接箍定位器和伽瑪射線傳感器能夠?qū)︺@頭深度進行確認。鉆頭深度精確的判定在深井作業(yè)，特別是在尋找開窗點時，尤為關(guān)鍵。該定向工具能使CT司鉆更好地控制井眼方向。反扭矩的影響能立即得到補償。與第一代定向工具相比，工具面的改變能在鉆進中進行，從而節(jié)省了

35、很多時間。在切線段該定向器可用于旋轉(zhuǎn)該BHA的動力部分，這就減少了為更換BHA組件而提下鉆的需要。BHA的旋轉(zhuǎn)可降低切線段的曲率，從而減少CT和安裝在井中的任何完井裝置下入時的阻力。來自內(nèi)部壓力和環(huán)空壓力傳感器的壓力數(shù)據(jù)可以幫助司鉆優(yōu)化馬達性能。壓力監(jiān)測有助于在欠平衡鉆井中減少氮氣的消耗量。對環(huán)空壓力進行控制可優(yōu)化機械鉆速，并可用于監(jiān)測井眼清洗效率。保持適當?shù)木讐毫?，可將地層損害降至最小。電纜遙測裝置可保證較高的數(shù)據(jù)傳輸率，有助于優(yōu)化作業(yè)過程。數(shù)據(jù)傳輸與鉆井期間使用的液體類型無關(guān)。該BHA目前僅利用了很少一部分電纜傳輸量，這將允許增加更多的傳感器來提高BHA的地層評價能力。 貝克休斯連續(xù)油管

36、鉆具組合特點 斯倫貝謝連續(xù)油管鉆具組合斯倫貝謝連續(xù)油管鉆井BHA將定向時間降為零，并且使用電纜遙測技術(shù)，有助于保持鉆頭在井底并進行鉆進。該工具的特點是有一個套管接箍定位傳感器，以及一個伽瑪射線傳感器，它們來提供鉆頭處的深度對比。這一切有助于降低通常出現(xiàn)在CT 作業(yè)中的深度誤差。內(nèi)部和環(huán)空壓力傳感器可在正常和欠平衡鉆井條件下為鉆井優(yōu)化提供數(shù)據(jù)參考。該BHA 的標準外徑為2-7/8in，它包括一個非連接裝置和一個專門用于CT 作業(yè)的鉆井頭。 方向及井斜傳感器該新型BAH 的另一項設(shè)計特點就是在一切可能的地方使用了現(xiàn)已成熟的技術(shù)。該方向及井斜傳感器是由目前應(yīng)用于其他MWD 工具包的傳感器改進而來。這

37、些傳感器靠近鉆頭的程度(6.4m) 及在方向和井斜測量1的精確度保證了定向司鉆能獲得可靠的數(shù)據(jù)，從而做出正確判斷。精確的方向傳感器和良好的方向控制允許設(shè)計小靶區(qū)鉆井。 地層評價地層評價由伽瑪傳感器提供。這種標準的、可靠的傳感器屬于現(xiàn)有小井眼MWD 設(shè)備，可用來進行地層評價及地質(zhì)導向。在鉆井或測井中都能獲取數(shù)據(jù)。這種新型BHA 能用于薄地層的鉆進并通過地質(zhì)導向最大限度延長井眼的有效長度。 斯倫貝謝連續(xù)油管鉆具組合 深度對比在CT 作業(yè)中經(jīng)常出現(xiàn)深度誤差，這些都是由于當CT 被推入井眼時其彎曲所致。其它一些因素, 如因溫度、管柱拉伸和在地面測量裝置的滑動的影響而引起的伸長或壓縮都會產(chǎn)生深度誤差。在

38、模擬這些情況的同時，總是有一些值不確定，如CT 末端的位置及鉆頭的位置。該新型BHA 內(nèi)裝有傳感器，有助于降低深度測量上的誤差。新型BHA 中還包括有套管接箍定位傳感器，這一裝置可用來在套管內(nèi)精確定位測量深度，這在再鉆井中是很重要的，這樣可確保造斜器的坐放位置及在隨后的磨銑作業(yè)中可避開套管接頭。在深井中，如果沒有套管接箍定位器，深度誤差就可使造斜器置于套管接頭處。套管接箍定位器已用于確定套管磨銑段的位置，從而確定造斜點的位置。套管接箍定位器也可用于在剛進入裸眼井前校正井深。另一種用于深度校正的傳感器是伽瑪射線傳感器。它可以通過識別已知地層或?qū)游粊泶_定深度。該傳感器通常在裸眼段造斜以及鉆造斜段時

39、使用。這種深度校正方法依賴鉆過的可識別地層的信息。不管怎樣，只要存在這種可識別地層，伽瑪射線傳感器就能夠提供一個最可靠的深度校正方法。 斯倫貝謝連續(xù)油管鉆具組合 壓力傳感器這種新型BHA 配備了壓力傳感器，可以測量內(nèi)部(CT 內(nèi)) 壓力和外部(環(huán)空) 壓力，這樣可以優(yōu)化鉆進過程。穿過馬達的壓降用于優(yōu)化鉆井馬達的性能，利用這些信息可以使馬達在最佳扭矩下保持運轉(zhuǎn)，以最大限度提高機械鉆速。馬達故障顯示器數(shù)據(jù)每兩秒傳輸一次，使司鉆可以對馬達運行進行高水平控制。CTD的一項推廣性應(yīng)用是進行欠平衡鉆井。如果該項技術(shù)能夠得到安全和經(jīng)濟地使用，則確定環(huán)空壓力是主要的。該新型BHA 中的環(huán)空壓力傳感器可持續(xù)控制

40、影響液體靜壓力及環(huán)空循環(huán)壓力的因素。在注入氣體產(chǎn)生欠平衡狀態(tài)的地方，可以通過控制氣體的注入量來優(yōu)化馬達性能，從而降低泵送費用及流體費用。環(huán)空流速高，特別是采用氣體時，經(jīng)?？砂l(fā)生由于摩擦壓力損失導致的井下壓力增加。在達到這一點時，施加于井底的壓力隨氣體注入量的增加而開始增加，如發(fā)生了這種情況，該井可回到過平衡狀態(tài)，這一切借助井下壓力測量很易于識別。如果為使地層損害降至最小程度而采用欠平衡鉆井，則要求能控制環(huán)空壓力，從而避免流體侵入儲層。在進行長水平段鉆進時，鉆頭處的壓力測量對考慮水平段的壓力損失是必需的。采用這種方法，井底的地層損害能夠避免。 斯倫貝謝連續(xù)油管鉆具組合 壓力傳感器環(huán)空壓力的監(jiān)測可

41、在井眼不穩(wěn)定或井眼清洗不好時提前告警，從而采取措施，減少這些問題的發(fā)生。優(yōu)化鉆井液流變性來提高井眼清洗，并將循環(huán)壓力降致最小。因為數(shù)據(jù)是由電纜傳輸，則該新型BHA可在泵送時或停泵時測量井底壓力。由于小井眼中環(huán)空間隙小，因此井控變得更為關(guān)鍵。通過縮短井涌檢測時間和在壓井作業(yè)時更好地控制井下壓力，使用環(huán)空壓力測量可將井噴風險降致最低。在欠平衡鉆井中，通常鉆進過程中可能會發(fā)生地層流體進入井中的情況。因此，應(yīng)采用壓力傳感器來優(yōu)化這些液體和正在泵送的流體的流量，從而保持欠平衡的狀態(tài)。在作業(yè)開始以前，特別是在鉆氣井時、或者是在鉆進中有氣體從地層中產(chǎn)出時，模擬氣體流入井中所產(chǎn)生的影響是必不可少的。現(xiàn)有軟件模

42、型可以用來確定流動對井眼和對井眼清洗的影響，根據(jù)推薦的作業(yè)可制定可能發(fā)生的事故的處理計劃。環(huán)空壓力的檢測將確保該井眼按照設(shè)計參數(shù)進行鉆井，同時應(yīng)有一個適宜于司鉆進行井控操作超出這些參數(shù)的計劃。 斯倫貝謝連續(xù)油管鉆具組合 數(shù)據(jù)傳輸一種標準的絕緣型電纜用于給定向器提供動力，同樣也用于從BHA 上或向BHA 發(fā)送和接收數(shù)據(jù)。采用泥漿脈沖遙測技術(shù)傳輸數(shù)據(jù)最大可能的傳輸速度為36 字節(jié)/秒，而采用電纜技術(shù)傳輸數(shù)據(jù)，其傳輸速度可達100k字節(jié)/秒。電纜裝置除了數(shù)據(jù)傳輸?shù)降孛娴乃俣雀咭酝?，還能把控制指令傳送往BHA，這樣就可以更換數(shù)據(jù)傳輸轉(zhuǎn)換器，從而優(yōu)化正在進行的作業(yè)的數(shù)據(jù)傳輸。地面接收到的信息是實時有效的

43、。在進行導向鉆井、持續(xù)旋轉(zhuǎn)鉆井及測井時都可傳輸數(shù)據(jù)。電纜數(shù)據(jù)傳輸避免了泥漿脈沖遙測技術(shù)通過可壓縮流體傳輸所引起的一些問題，因此，這種新型BHA 能用于氣體混入泵送流體中時，例如，在欠平衡鉆井期間。該工具可在地面組裝，或是在井下組裝。它可將最為重要的數(shù)據(jù)以最高頻率發(fā)送至地面。電纜裝置的這種性能還可以允許在將來裝上其它的傳感器。 斯倫貝謝連續(xù)油管鉆具組合 地面裝置新型BHA 使用的地面裝置是根據(jù)目前應(yīng)用于MWD/LWD和地質(zhì)導向設(shè)備的軟件進行設(shè)計的。該裝置是把定向鉆井、傳感器及由BHA傳輸?shù)膸r石物理數(shù)據(jù)與地面測量結(jié)合起來。該解釋軟件把這些信息進行轉(zhuǎn)換，并以現(xiàn)場指導小組可采用進行鉆井過程優(yōu)化的格式顯

44、示出來。該裝置還可在一個高分辨率的監(jiān)視器上同時顯示許多不同的窗口。地面裝置很容易獲得不同窗口數(shù)據(jù)多座標圖以及硬盤拷貝記錄。為了保持CTD 作業(yè)占地面積小、設(shè)備數(shù)量少，地面設(shè)備的需求量已降至最低程度。便攜式計算機可用于接收及顯示這些信息。如果CT 控制室地方足夠大，記錄人員可在此工作。如CT 控制室太小，該裝置可以在任何適宜工作的地方建立，且現(xiàn)場并不需要記錄室。子監(jiān)視器可安放在CT 控制室、用戶代表室及現(xiàn)場工程師辦公室內(nèi)。如客戶需要的話，通過采用衛(wèi)星通訊，這些數(shù)據(jù)也能夠在用戶總部辦公室內(nèi)顯示。 斯倫貝謝連續(xù)油管鉆具組合 定向工具該新型BHA的主要特點之一是有一個改進的定向器。該設(shè)計避免了提離井底

45、調(diào)整工具面的時間。該定向器由電力馬達直接提供動力，并由安裝于CT中的電纜控制。這就允許對該定向器進行實時定向。定向器可產(chǎn)生高達1000 lbfft的扭矩，這足以克服BHA配合使用的鉆井馬達所產(chǎn)生的扭矩。該工具的工具面可以以1的增量來轉(zhuǎn)動，并可以順時針或逆時針轉(zhuǎn)動。這樣，定向司鉆可對BHA進行全面控制，使其能精確導向，進入目標層。通過將工具面數(shù)據(jù)輸入到地面裝置的計算機中來對工具面進行校正。除了增加控制外，該定向器還能在任何方向持續(xù)旋轉(zhuǎn)。在CT鉆井的一般機械鉆速下，該定向器以1r/min的轉(zhuǎn)速旋轉(zhuǎn)，可降低井眼曲率；同時，這種旋轉(zhuǎn)也減少了以往為改變BHA定向組件而起下鉆的需要。旋轉(zhuǎn)BHA動力段的能力

46、將產(chǎn)生較直的切線段，這將降低CT的阻力，使其在過度彎曲或鎖定以前可以向前鉆進。小曲率井眼也使定向工作比較容易完成。 斯倫貝謝連續(xù)油管鉆具組合The VIPER slimhole CTD MWD and motor system provides real-time drilling information, precise orientation control and pressure sensors to monitor bottomhole pressure. The VIPER system is a wireline-controlled bottomhole assembly (B

47、HA) that consists of a downhole orienting tool for directional control and an MWD system for directional measurements. Orienting-while-drilling ensures accurate, continuous directional control. The VIPER system uses an electromechanical orienting tool that rotates in either direction, continuously o

48、r in 1 increments, to control the wellpath. The downhole adjustments can be made in real time by inputting the desired toolface corrections into the surface computer of the VIPER systems. 斯倫貝謝連續(xù)油管鉆井特點Straight and smoothThe slow, continuous rotation of the VIPER tool enables it to drill boreholes tha

49、t are straighter and smoother than can be achieved with conventional methods.Generating up to 1000ft-Ibf torque, the VIPER tool rotates at 1 rpm to eliminate the effect of the fixed-bend motor. The straighter wellbore provides: faster penetration rates reduced drag and longer reach easier running of

50、 completions more efficient workover operations better hole cleaning 斯倫貝謝連續(xù)油管鉆井特點Staying on trackUsing gamma ray and casing collar locator sensors, drillers can reduce the depth discrepancies often encountered in CT operations. These discrepancies are usually caused by buckling of the CT as it is pu

51、shed into the wellbore. The gamma ray sensors of the VIPER system identify formations, or horizons within them, for reliable depth correlation. The casing collar locator sensor is also useful during reentry drilling for accurate depth control.The VIPER system BHA can be oriented while drilling. Fine

52、 downhole adjustments are possible by inputting the desired toolface corrections into the surface computer system. The orienting tools ability to turn continuously allows the driller to rotate and slide while drilling curves and laterals, resulting in faster rates of penetration and less tortuous we

53、ll paths. 斯倫貝謝連續(xù)油管鉆井特點 斯倫貝謝連續(xù)油管鉆井特點Staying on track Linked to the orienting tool is a reliable and robust directional surveying package. Azimuth, inclination and toolface measurements are transmitted to the surface through its high data rate wireline telemetry system to give the driller more control

54、 for sophisticated well paths and tighter targets. The tools gamma ray sensor can be used for geological correlation. This allows a simple form of geosteering to increase the accuracy of the well path. Some geological interpretation is possible and the gamma ray sensor can be used to recognize marke

55、r formations and so aid depth correlation.Pressure controlThe VIPER system logging module uses advanced pressure sensor technology to monitor internal (CT) and external (annular) pressure during drilling, tripping and circulating the well. When drilling underbalanced wells with a gasified liquid flu

56、id, the annular pressure sensor allows greater control of the hydrostatic pressure acting on the reservoir. This helps the driller to avoid killing the well and damaging the formation by fluids or solids invasion.The pressure sensor measurements are also used to keep the motor running at peak perfor

57、mance for maximum penetration rates, and to prevent stalling(滯動). 斯倫貝謝連續(xù)油管鉆井特點 斯倫貝謝連續(xù)油管鉆井特點Working with the wirelineUsing a wireline system for data transfer means than the VIPER tool can transmit high data volumes much faster than systems than rely on mud-pulse transmission. Drilling information, f

58、or example, can be transmitted at rates of around 100,000 bits per second in the VIPER system wireline, compared to only 36 bits per second in mud pulse transmission. Wireline telemetry can transmit data to the surface regardless of the drilling fluid being used. Data are transmitted equally well in

59、 underbalanced or overbalanced conditions. The data rates are very high, giving the driller almost real-time information from the sensors. Because data transmission is instantaneous, no time is lost waiting for mud pulses to be established.The high data-transmission capacity of the wireline will all

60、ow the addition of other LWD tools to the BHA in the future. 斯倫貝謝連續(xù)油管鉆井特點Working with the wireline Designed for easy maintenance and handling, the VIPER tool can be split into two parts, each with built-in check valves to allow deployment into wells under pressure. Tool length has been minimized to