摘要
苏69X井是霸县凹陷文安斜坡苏桥南鼻状构造高点的双靶预探井,设计井深为3924 m。该井目的层漏失严重,在沙一段至沙三段多次发生钻井液只进不出现象;馆陶组至沙三段地层有多套储盖系统,封固段长,不同储盖系统地层压力差异大;工程上要求少下扶正器,使得在斜井段套管偏心难以避免;为减轻压漏地层的风险, 水泥浆上返速度受到限制;对水泥浆的触变性要求较高。该井选用低密度多凝水泥浆体系,使水泥浆液柱压力略大于地层漏失压力,以做到“压而不漏、活而不喷”,实施近平衡固井;并在低密度水泥浆中加入增强材料(PZW),用 PZW自身的几何尺寸特点调整水泥浆固相的颗粒级配,减少固相颗粒之间空隙,以提高水泥浆的稳定性,进而达到提高水泥石强度的目的;根据施工时间的需要,使用缓凝剂H88L、BXR-200L调整各段浆体凝结时间,使封固段内水泥浆柱在凝结时间上形成梯度,避免失重,确保压稳地层。该井通过选用优质处理剂调整低密度增强水泥浆性能和配合相应的施工措施,成功地完成了漏失量大、地层复杂的苏69X井的固井作业。
Su 69X well is a wildcat well with dual-targets of 3924 m located in the nose structure highs in the south of Su Qiao on Wen An slop of Ba Xian sag. A severe lost circulation occurred when drilled in the formation of interest, and no returns frequently happened during the section of Sha-Ⅰ to Sha-Ⅲ. The section from Guan Tao to Sha-Ⅲ required a long productive interval and had multi overburdens among which had a large formation pressure difference. The lateral movement of casing in the inclined section was difficult to void due to few centering devices required in drilling practice. The uphole velocity of slurry was limited by the risk of lost circulation and thus better thixotropic property of slurry was demanded. Low density gel slurry system was selected to conduct near-banlanced cementing. And also, reinforcing material (PZW) were added into the slurry which can reduce the interparticle gaps of solids by adjusting the particle size distribution to improve the stability and further strength of slurry. In accordance of the time of operation, the retardants of H88L, BXR-200L were used to condition solidifying time of the slurry for different intervals and a time gradient of solification can form in the productive interval. Thus, the loss of weight can be prevented and the stability of formation can be guaranteed. The low density and reinforcing slurry with high quality was developed by using quality additives. Coupled with proper on-situ operation, the cementing job of Su-69X well which had a great quantity of loss and a complicated formation was accomplished successfully.
出处
《钻井液与完井液》
CAS
北大核心
2006年第1期78-79,83,共3页
Drilling Fluid & Completion Fluid
关键词
低密度水泥浆
近平衡固井
固井质量
水泥浆配方
苏69X井
low density slurry, near-banlanced cementing, cement job quality, formulation for slurry, Su 69X well
