| 摘要: |
| 针对深水探井钻井可参考信息有限的特点,提出改进的计算上覆岩层压力梯度和建立时深关系的方法。利用 概率统计理论,研究Eaton法中各个参数对最终结果的影响规律和相互关系，提出基于层速度的有效应力法与Eaton 法联合预测地层孔隙压力的方法，建立了含有可信度的地层孔隙压力剖面v使其不再是一条单一的曲线，而是具有 可信度信息的区间。可信度越大,得出的地层孔隙压力梯度区间越大,其不确定范围越大;反之，虽然压力梯度的不 确定范围缩小,但其可信程度也随之降低;地层孔隙压力的异常高压程度越剧烈,其压力区间也越大。西非深水区 域一口探井计算结果与实测压力值具有较好的一致性。 |
| 关键词: 深水钻并 地层孔隙压力 不确定性 可信度 概率分析 |
| DOI： |
| 分类号: |
| 基金项目:国家“863”计划项B(2006AA09A106)和中国石化集团公司项B(JP0712) |
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| An approach to determining pre-drilling formation pore pressure with credibility for deep water exploration wells |
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KE Ke, GUAN Zhi-chuan, ZHOU Hang
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(College of Petroleum Engineering in China University of Petroleum, Dongying 257061，China)
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| Abstract: |
| For the lack of reference data from offset wells of deep water exploration well drilling，an improved approach to determining overburden pressure gradient was presented and the relationship of time and depth was established. With the probabilistic theory, the influence of each parameter on result and the interrelationship between them of Eaton model were studied. An approach to pore pressure prediction was provided by a combined methodology of Eaton model and effeclive-stress method using interval velocity data, and the pore pressure profile with credibility was established. This pore pressure profile is not a single curve but the interval with credibility information. Higher the credibility or the degree of overpressure, wider the interval of pore pressure gradient and the uncertainty area，otherwise, although narrower the uncertainty area, lower the credibility. The results of a well in West Africa deep water area agree well with ihe field test value. |
| Key words: deep water drilling formation pore pressure uncertainty credibility probabilistic analysis |
