大港油田板深7井钻井液工艺技术

板深7井是大港油田板桥古潜山构造的一口重点超深探井,完钻井深5191.96m。该井针对不同的地层采用不同的钻井液体系。二开选用聚合物钻井液和相应的技术措施,有效地抑制了地层造浆;三开选用硅基防塌钻井液,性能保持低粘度、低切力、高动塑比,利于携砂、脱气,具有良好的流变性和防塌性;四开实施欠平衡钻井技术,采用无固相钻井液体系。现场应用表明,在清水中加入1％的碱式碳酸锌、0．2％的缓蚀剂和适量烧碱,用可溶性盐来调节钻井液密度,防止了二氧化碳、硫化氢对钻具的腐蚀,保护了油气层,满足了欠平衡钻井的施工要求。

Drilling fluid technology in well Banshen-7 of Dagang Oilfield

Well Banshen-7 is an important exploratory well drilled in the buried hill of Dagang oilfield, with a total depth of 5191. 96 m. Different drilling fluid system is used for different intervals, more specifically, polymer drilling fluid is used in the 17 l/2"hole, to effectively inhibit mud making in this section; silicate-based anti-sloughing drilling fluid is selected in the 12 l/4"hole, and this system has low viscosity, low shearing force and high dynamic to plastic ratio, which are good for cuts transportation and degasing; underbalanced drilling technology is applied in the 8 1/2"hole, and solid free drilling fluid is used to minimize formation damage. By adding 1 % caustic zinc carbonate, and 0. 2% corrosion inhibitor and a certain amount of caustic soda, drill pipe corrosion caused by carbon dioxide and hydrogen sulfide is prevented.