乐东221气田A14H井表层定向及扩眼钻井技术

为解决南海莺歌海盆地乐东 22-1 气田表层松软地层定向造斜扩眼钻进困难、邻井相碰及易产生新井眼等钻井工程技术难题,提出了一种先钻小尺寸领眼,再用新型三级固定翼扩眼器定向扩眼,然后下入套管的海洋表层钻井技术.结合随钻测量仪和电子陀螺测斜仪钻进乐东 22-1 气田A14H井表层时,先用φ250.8 mm钻具定向造斜、钻小领眼,再用φ254.1 mm×φ349.3 mm×φ444.5 mm新型扩眼器将领眼定向扩眼至φ444.5 mm,下入φ339.7 mm表层套管并固井.现场应用表明,该技术解决了丛式井表层防碰难题,保障了疏松地层的造斜钻进效果,防止了钻井中扩眼钻具对领眼井造斜效果的不利影响,对后续类似井的钻井具有一定的借鉴价值. 

Directional Drilling & Reaming Technology in the Shallow Formation of Well A14H in the LD22-1 Gas Field

In order to solve problems that occurred when drilling shallow soft formation in the LD22-1Gas Field, in the Yinggehai Basin of the South China Sea,including problems in directional drilling,reaming,building angle, borehole collision of the adjacent wells,a new technology was developed.It involved drilling a small-sized pilot hole at first,and then using special three-stage reamer to directionally reaming it,followed by then running surface casing.Combined MWD with gyro inclinometer,a small pilot hole of φ250.8 mm was drilled with directional drilling tools in Well A14H in LD22-1 Gas Field,and then it was reamed to the φ444.5 mm by the special reamer with three-stage reaming sizes of φ254.1 mm×φ349.3 mm×φ444.5 mm,finally the φ339.7 mm casing was run in hole and cemented.Drilling practices showed that the technology successfully prevented the borehole from colliding in cluster wells in shallow formations successfully.It also ensured the effect of directional drilling and building up,and eliminated the unfavorable effect of reamer on building up in pilot hole.The study concluded that it would be an useful reference for drilling in similar shallow soft formations.