摘要
位于新疆牙哈地区的YH23-2-4井是在某直井基础上填井侧钻而成的凝析气田水平井。实钻中,克服了斜井段长、水平位移大、井眼轨迹控制难度大,以及摩阻扭矩大、大斜度井段钻井液携岩困难、钻具疲劳破坏等诸多技术难点,井眼轨道设计采用直—增—增—增—平五段制剖面类型;深井侧钻坚持小钻压、小排量和稳定的工具面的原则,优选适宜的钻具组合;斜井段为满足轨迹对造斜率的需要,选用高速牙轮钻头配合1.75°螺杆钻具及MWD施工;水平段钻进中,合理确定滑动钻进和复合钻进的比例,根据LWD实时测井曲线与邻井测井曲线对比结果,及时调整靶点垂深,控制井眼轨迹在储层中有效穿行,降低钻井风险;采用聚磺类钻井液体系,在膏泥岩地层井底温度升高、井壁缩径、黏切升高、失水量大的情况下,适当提高钻井液密度,并加入一定量的原油和抗高温高压、降低失水量的钻井液材料,以增加钻井液的润滑性和流变性,保证井眼稳定和井下安全。
YH23-2-4 well is a sidetrack horizontal one in a condensate field located in Yaha district of Xinjiang,whieh was a straight one before.Many technical difficulties were overcome during the drillling prac- tice of the well,including long deviated well intervals,long horizontal displacement,difficuhy on well control ,and big friction torque ,being difficult on carrying rock of the drilling fluid in＇ the deviated well inter- vals and endurance failure on drilling rig and so on.Well trajectory was designed as five-interval profile of vertical-incremental-incremental-incremental-horizontal ones.The principle of deep well sidetrack was type small bit weight,low delivery rate and deviated well intervals,high-speed meeting the demand of build-up stable tool face through optimization of cone bit and 1.75~helicoid hydraulic rate by well path.During the drilling suitable make up motor and MWD of the horizontal scale of slide and combined drilling was fixed,and vertical depth of the targets was adjusted ing to the correlation would be decreased of string.At the was selected for intervals, rational in time accord- between LWD real-time bore log and the bore log of the well nearby;and drilling risk through effective well path in the reservoirs.Polysulfonate drilling fluid system was applied.In the mudstone formation,density of the ture increasing,borehole wall reducing,viscosity of crude oil and drilling as to make the drilling safety will be ensured. drilling fluid should be big enough when bottom hole tempera- and shear force increasing and more filter loss.Certain quality fluid with anti-high temperature and pressure and filter loss reducing was added so fluid have better oiliness and rheological property,and stable wellbore and subsurface safety will be ensured.
出处
《中外能源》
CAS
2010年第2期52-55,共4页
Sino-Global Energy
