AFP1水平井钻井液技术

AFP1井是位于江苏油田AF复杂断块小油田上的一口中曲率半径水平井，水平段长434．21m。上部地层遇水易膨胀缩径，中下部地层有高压盐水层．钻井液侵污明显，储层泥岩水化能力强，携岩问题突出。采用正电胶一小阳离子聚合物钻井液体系。经现场应用表明，该钻井液在二开直井段较好地控制了钻井液滤失量，减少了滤液渗入地层，防止了地层水化膨胀；三开直井段降低了劣质固相含量，保证钻井液具有良好的悬浮性能和流变性；水平段钻井液具有良好的润滑性能．改善了泥饼质量，保证井壁稳定，破坏岩屑床并及时将岩屑携带出。该钻井液能减轻液相对油气层的损害，AFP1井初试油求产，日产原油达70多吨。该体系性能稳定，易于维护处理，保证了快速完井。

Drilling fluid technology for the horizontal Well AFP1

Well AFP1 is a medium curvature radius horizontal well located in a complex fault hlock, with a horizontal interval of 434. 21 m. The surface formation is easily hydrating and inflating, while in the medium and lower formations exist high-pressured saltwater zone, the problems of drilling fluid contamination, shale hydrating and cuttings transportation are remarkable. Positive colloid-micro cation polymer drilling fluid system was applied in this well. Field using showed thai this system could effectively control the drilling fluid filtration in the vertical 2nd section, and it could also minimize the invasion of filtrate into for mation and prevents formation hydration; the content of negative solids was effectively reduced in the 3rd vertical section, and good cuttings transportation and rheology was also obtained. When used in the horizontal interval, it displayed good lubricity, improved mud cake quality, good wellbore stability, and effective cuttings bed removing and cuttings transportation. This system could reduce the formation damage because of fluid contamination, and the initial production test of Well AFP1 obtained a production rate of o-ver 70 tons per day. This drilling fluid was stable and easy for maintenance, and ensured the fast completion operation.