对东营凹陷沙河街组地层水化学研究结果表明：沙河街组地层水为矿化度较高，阴、阳离子分别以Cl^-和Na⁺+K⁺为主的氯化钙型水，r_Na/r_Cl平均值在0.92～1.12之间，r_SO4×100/r_Cl平均值在3.68～5.73之间，r_Cl—Na/r_Mg平均值在-0.52～5.37之间；剖面上，沙河街组地层水化学成分和离子比值随深度表现为阶梯式增加型、增加—减小交替型和变化混乱型3种变化类型。平面上，沙河街组矿化度由凹陷边缘向中心递增，并且沙三段—沙一段矿化度高值区主要分布在中央断裂带附近；沙河街组现今地层水总体处于封闭的流体动力环境，但同一地层不同构造单元的地层水的流体动力环境相差较大，油气的聚集和保存条件也相差较大；在地质历史时期流体曾沿中央断裂带由深层向浅层运移，且中央断裂带受大气淋滤水影响较弱，有利于后期油气的聚集和保存。

The formation water chemistry of Shahejie Formation in Dongying Sag shows that: (1) The water is of CaCl₂ type with high TDS and contains mainly cations K⁺+Na⁺ and anion Cl^-. Their average r_Na/r_Clis in the range of 0.92~1.12, the r_SO4×100/r_Cl averages 3.68~5.73, and the metamorphic coefficient (r_Cl—Na/r_Mg) ranges from -0.52 to 5.37. (2) The chemical composition and ionic ratio of the formation water present ladder, alternate and mixed variations with depth. While horizontally, the TDS of Shahejie Formation increases from the sag′s edge to the center, and the high TDS of Sha\|3 to Sha-1 Member is distributed in the central fault belt. (3) Shahejie Formation water is in the closed fluid dynamic environment now, however, there are great differences in the fluid dynamic environment and the conditions of oil & gas accumulation and preservation in different belts of the same member. (4) Fluid migrated from deep to shallow layers along the central fault in the geologic history, and it was excellent for hydrocarbon accumulation and preservation due to the weak influence on the belt of atmospheric leaching.