5.油气层损害诊断

DST Trace Showing Extreme Damage in a High Productivity Zone
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Exercise in Class
1。指出下列测试卡片曲线中，A、B两口井是否存 在损害，并说明理由。 2。油田开发中哪些作业可以增加渗透率
曲线A
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四大类型
物理损害
化学损害
生物损害 热力损害
油气层损害类型及其分布结构
大 类 亚 类 三 级 四 级 作业环节
微粒运移 固相侵入 钻完井液固相 注入流体固相 水基工作液 相圈闭 物理作用 机械损害 射孔损害 应力损害 岩石—外来 流体不配伍 化学作用 油基工作液 泡沫状油 岩面釉化 岩粉挤入 压实损害 剪切膨胀 地层压实 敏感性损害 处理剂吸附 有机垢沉积 地层流体—外来 流体不配伍 润湿性反转 分泌聚合物 生物作用 腐蚀损害 流体酸性化 矿物溶解 热力作用 矿物转化 润湿性变化 热力采油为主 注 水 和 EOR 过 程为主 无机垢沉积 乳状液堵塞 粘土矿物损害 非粘土矿物损害 聚合物、阴离子 石蜡、沥青沉积 盐类沉积、水合 物、类金刚石物 钻井完井、增 产改 造 、 修 井 、 注水注气、EOR 气 体 流 体 钻 井、斜井钻井 射孔完井 钻井、油气生 产 钻井完井、增 产改 造 、 修 井 、 注水注气、EOR


Figure 5-3C illustrates an invaded zone at a depth of 3700 feet where there is a separation between the 16" normal and 64" normal. Note that R16”- > R64”. Evaluation of the caliper log can give relative indications of permeability and probable invasion profiles.
油气层损害诊断
康毅力
西南石油学院石油工程学院 油 井 完 井 技 术 中 心
2004年04月05日
提 纲
0、损害机理及诊断概述 1、DST测试 2、测井分析 3、井史分析 4、相邻井生产动态对比 5、压力不稳定试井分析 6、节点系统分析 7、生产效率剖面 8、生产测井 9、岩心分析
油气层损害机理
损害描述
天然损害 类型 （生产井） 微粒运移 出砂 无机垢沉积 方式 有机垢沉积 乳化堵塞 相对渗透率效应 诱发损害 （施工作业） 固相侵入 润湿性反转 酸反应二次沉淀 细菌 与地层流体不配伍 与岩石矿物不配伍
储层损害诊断方法 Methods for Recognition of
1、钻柱测试（Drill Stem Tests）
In
the early stages of exploratory drilling into a new formation, Drill Stem Testing is normally used to confirm the production potential of a hydrocarbon show However, if geochemical analysis of drill chips and cuttings establishes the presence of hydrocarbons, but DST shows the tested interval to be non-productive, then formation damage possibly exists Analysis of the pressure versus time data generated during DST can be used semi-quantitatively to determine the severity of damage by calculating the skin. It is, however, desirable to exercise caution during initial DST, since pressure surges and high drawdown can initiate fines movement. Review of prior operational history is then necessary to establish which aspect ofthe drilling process may have given rise to damage.
– The following figure shows a typical DST output illustrating a high permeability damaged zone. Notice the following features that are characteristic of damage:
Table 5-1 Depth of Invasion zero or very shallow invasion Moderate invasion Deep invasion Very deep invasion Logging Devices RLLS RILM RILD RE RLLS > RILM RILD RE Rxo RLLS > RILM > RILD RXO RLLS RILM > RILD


Figures 5-3A and 5-3B show typical resistivity profiles in flushed, transition and uninvadedzones for a water and oil bearing zones, respectively. In both figures, the resistivity of the mud flushed zones, Rxc) was greater than the resistivity of the uninvaded zone, RE. Combination of the Dual Induction Log and the Laterolog are usually sufficient in most cases to indicate the depth of filtrate invasion. The table below shows the different combination logging devices for various depths of invasion, where Rxo > RE.
3、井史分析（Well History Review）

If problems are identified by DST and logs, further investigation is still necessary to pinpoint what aspect of the drilling/completion program is responsible for the apparent poor formation response 作业史分析 Daily drilling/ cementing/completion reports, mud and completion, workover andwell stimulation fluid programs should be reviewed (Allen). 滤失量、pH值、钻速随深度变化Fluid loss, pH and ROP data shouldbe plotted as function of depth to help identify any zones where high pH-filtrate loss had occurred. Such zones are good candidates for damage.
Short
radius curve along CDE* An almost flat slope along DE A sharp rise after closed-in period as along EF A high differential pressure between a closedin and final flow pressure (EG)


润湿性改变 水锁 凝析液锁 液相圈闭（水，油） 气锥或水锥 毛管压力的改变 乳状液堵塞 粘土膨胀 微粒运移 云母解体


无机垢 注ＣＯ２导致的无机垢 酸化引起的二次沉淀 碳酸盐溶解—沉淀 酸渣 有机垢—石蜡，沥青沉积 外来固相的堵塞 油气层固相物堵塞，出砂 细菌损害 应力损害
诊断技术


DST测试分析
测井分析


生产效率剖面
生产测井
生产史分析
相邻井产量对比
岩心实验分析
井下照相
压力不稳定试井分
析
井下取样分析
节点分析
提 纲
0、损害机理及诊断概述 1、DST测试 2、测井分析 3、井史分析 4、相邻井生产动态对比 5、压力不稳定试井分析 6、节点系统分析 7、生产效率剖面 8、生产测井 9、岩心分析
– An individual well analysis then quantifies whether or not the well is producing topotential. If not, why? And the production potential behind pipe.
Formation Damage
低产原因
储层物性条件差
—饱和度、孔隙度、渗透率、裂缝
存在储层损害 作业因素,如完井作业中：
—射孔参数不合理（孔眼密度低、孔眼太小，
深度不够，打开不完善） —水泥环质量差、强度不高等
损害可能存在的标志



压力与产量关系变化波动很大 产量低于经济下限 产量要比中途测试、岩心分析、测井计算所预测值 低得多 同一油气藏，储层物性完全相同，但产量差异很大 生产井出砂 测试时出现表皮效应 有机结垢和无机垢沉积 注入能力急剧下降，措施或处理周期短
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2、测井分析
•测井曲线上 的泥浆侵入 响应
Mud
Invasion Effects on
中子孔隙度降低
Well Logs
感应电阻率降低
滤液侵入程度和深度可以从深、中、浅电 阻率测井或双感应测井曲线进行半定量评价

The degree and depth of filtrate invasion during drilling can be estimated from deep, medium and shallow resistivity devices (e.g Laterolog) or conductivity devices such as dual induction logs or combinations thereof (e.g Induction-Laterolog). These devices will give semi-quantitative indications of possible damage during production. Analytical models presented by Hassen for describing filtrate invasion can also be used to estimate the depth of invasion particularly in cases where the depth of investigation of the logging tool is limited.