摘要
深井、复杂井目前主要面对的钻井难题是如何在窄钻井液密度窗口中安全钻进,而控制压力钻井技术则可以解决上述难题。控制压力钻井主要包含控压钻井(Managed Pressure Drilling,缩写为MPD)技术与微流量控制(Mi-cro-Flux Control,缩写为MFC)钻井技术。为促进国内引进、吸收、应用以上新技术,从钻井技术原理和钻井设备及特点这两个方面,将MPD与MFC进行了详细对比。结论认为:①MPD可以精确控制井底压力,实现平衡或近平衡钻井,设计的钻井液密度低于常规钻井液密度,当循环钻进时需要通过液柱压力与循环压耗来平衡地层压力,当停止循环时井底压力则为液柱压力与回压之和,需要回压来弥补循环压耗以达到平衡状态;②MFC是在MPD基础上研制出来的一种新钻井技术,它不仅满足了MPD技术的核心功能,而且还拥有了自己独特的技术特点——微流量(微进口流量和微出口流量)控制,能探测到早期的侵入与漏失,更精确地预见和控制有关事故的发生;③与MPD相比,MFC能探测到更小的井内总体流量的波动范围;④国内有必要尽快引进和吸收以上先进技术,用以提高钻井技术水平和解决窄钻井液密度窗口安全钻进问题。
The major drilling challenge in deep and complicated wells nowadays is how to perform safe drilling through formations with narrow drilling fluid density window and the managed pressure drilling(MPD) technology can solve this problem and it includes MPD and MFC(micro-flux control) drilling.For getting more knowledge of those two drilling technologies for their further promotion and wide application,comparison is made between them from aspects of the principles,drilling equipment and features.The following results are concluded.First,MPD can precisely control the bottomhole pressure to realize balanced drilling or near-balanced drilling,the designed drilling fluid density is lower than the conventional drilling fluid density.When the circular drilling is running on,the hydraulic column pressure and circulation pressure loss will be considered to balance the formation pressure;while the circular drilling stops,the bottomhole pressure will be equal to the hydraulic column pressure plus backpressure.Thus,the backpressure is exerted to set off the circulation pressure loss to achieve the balance.Second,MFC is further developed from MPD,it can not only meet the requirements for the main functions of MPD,but has its own unique features,that is,micro-flux(both influx and out-flux) control,being able to detect the intrusion and loss at the early stage and more precisely foresee and control potential accidents.Third,Compared with MPD,MFC can detect minor flux variation in the wellbore.Fourth,it is necessary to introduce those technologies into China to improve drilling technology and to perform safe drilling through formations with narrow drilling fluid density window.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2011年第2期82-84,129-130,共3页
Natural Gas Industry
基金
"十一五"国家油气重大科技攻关项目(编号:2008ZX05000-021-006)的部分研究结果
