石油钻探技术
石油鑽探技術
석유찬탐기술
PETROLEUM DRILLING TECHNIQUES
2014年
6期
18-24
,共7页
U形井%不确定性%连通%RMRS%协方差矩阵%误差椭球%误差椭圆
U形井%不確定性%連通%RMRS%協方差矩陣%誤差橢毬%誤差橢圓
U형정%불학정성%련통%RMRS%협방차구진%오차타구%오차타원
U-shaped wells%uncertainty%intersection%RMRS%covariance matrix%error ellipsoid%error ellipse
为了更好地使用旋转磁场测距导向系统(RM RS )来引导两井的精确连通,进行了 U形水平井连通过程中的相对位置不确定性分析。根据RM RS在连通中的引导过程,将相对位置不确定性分为由RM RS引起的测点相对正钻井井底的位置不确定性和由测斜仪引起的连通点相对测点的位置不确定性。采用井位不确定模型,得到由RM RS和测斜仪引起的相对位置不确定性的协方差矩阵。通过坐标转换,得到同一坐标系下的总协方差矩阵,并给出由总协方差矩阵确定的误差椭球(圆)。从实例计算可以看出,连通点与正钻井井底相距101.84 m时,误差椭球的半轴长度为3.75,1.90和2.66 m ;随着钻进的进行,相距10.00 m时,误差椭球的半轴长度为0.25,0.56和0.07 m。研究结果表明,由RM RS测得的相对位置误差随钻头的钻进不再积累而是逐渐减小,同时进行相对位置不确定性分析有利于实现两井的连通,并有效地指导RM RS的使用。
為瞭更好地使用鏇轉磁場測距導嚮繫統(RM RS )來引導兩井的精確連通,進行瞭 U形水平井連通過程中的相對位置不確定性分析。根據RM RS在連通中的引導過程,將相對位置不確定性分為由RM RS引起的測點相對正鑽井井底的位置不確定性和由測斜儀引起的連通點相對測點的位置不確定性。採用井位不確定模型,得到由RM RS和測斜儀引起的相對位置不確定性的協方差矩陣。通過坐標轉換,得到同一坐標繫下的總協方差矩陣,併給齣由總協方差矩陣確定的誤差橢毬(圓)。從實例計算可以看齣,連通點與正鑽井井底相距101.84 m時,誤差橢毬的半軸長度為3.75,1.90和2.66 m ;隨著鑽進的進行,相距10.00 m時,誤差橢毬的半軸長度為0.25,0.56和0.07 m。研究結果錶明,由RM RS測得的相對位置誤差隨鑽頭的鑽進不再積纍而是逐漸減小,同時進行相對位置不確定性分析有利于實現兩井的連通,併有效地指導RM RS的使用。
위료경호지사용선전자장측거도향계통(RM RS )래인도량정적정학련통,진행료 U형수평정련통과정중적상대위치불학정성분석。근거RM RS재련통중적인도과정,장상대위치불학정성분위유RM RS인기적측점상대정찬정정저적위치불학정성화유측사의인기적련통점상대측점적위치불학정성。채용정위불학정모형,득도유RM RS화측사의인기적상대위치불학정성적협방차구진。통과좌표전환,득도동일좌표계하적총협방차구진,병급출유총협방차구진학정적오차타구(원)。종실례계산가이간출,련통점여정찬정정저상거101.84 m시,오차타구적반축장도위3.75,1.90화2.66 m ;수착찬진적진행,상거10.00 m시,오차타구적반축장도위0.25,0.56화0.07 m。연구결과표명,유RM RS측득적상대위치오차수찬두적찬진불재적루이시축점감소,동시진행상대위치불학정성분석유리우실현량정적련통,병유효지지도RM RS적사용。
To effectively use RMRS to guide the accurate intersection of two U‐shaped horizontal wells ,the relative position uncertainty in the intersecting process was analyzed .According to the guiding process of RMRS for well intersections ,the relative position uncertainty was divided into two parts :the rel‐ative position uncertainty between the bottomhole being drilled and the measure point by RMRS ,and the relative position uncertainty between the intersection point and the measure point by inclinometer .The co‐variance matrix of relative position uncertainty caused by RMRS and the inclinometer was obtained by u‐sing a borehole position uncertainty model .Through the conversion of coordinates ,the total covariance ma‐trix was obtained in the same coordinate system ,and then the error ellipsoid and error ellipse were deter‐mined on the basis of the total covariance matrix .From the example it could be determined that w hen the distance from bottom‐hole drilled to the intersection point was 101.84 m ,the lengths of semi‐axes were 3.75 ,1.90 and 2.66 m respectively .With the drilling operation ,when the distance from bottomhole to in‐tersection point was 10.00 m ,the lengths of semi‐axes were 0.25 ,0.56 and 0.07 m .The result indicated that the relative position error measured by RMRS was no longer cumulative but decreased gradually .The analysis of relative position uncertainty being made simultaneously would help the realization of the inter‐section of two wells ,and guide the use of RMRS effectively .