钻孔施工过程中影响预测见煤深度因素的查找及校正实例

An Example of Search and Correction of Influencing Factors in Coal Intersecting Depth Prediction during Borehole Drilling

为准确评价勘查区内的水文地质条件,验证原有钻孔的施工质量,在距原7755号孔50m的地方施工了S06-1孔。施工发现,S06-1孔的标志层和煤层资料与原7755号相差很大,最大可达119.60m。究其原因是本区岩性软硬相间、岩层倾角大以及施工质量差所致。在仔细分析施工钻孔岩性的基础上,发现区内有一层灰褐色、含直径为1mm的石英泥岩较为稳定,可作为标志层对煤层进行预测,并以此提出了见煤深度预测公式,对该区煤层进行预测。预测结果与实际见煤深度很近,从而证明该标志层及预测公式可靠,可作为后续钻探施工指导依据。

To evaluate hydrogeological conditions in exploration area in accuracy, for examination of existing borehole operating quality, borehole S06-1 was drilled 50m apart from original borehole No.7755. The operation has found that marker bed and coal seam data of S06-1 have distinct differences with those of No.7755, the maximum value amounts to 119.60m. The actual causations include alternative soft and hard rocks, large strata dip angles in the area, as well as poor operation quality. Analyzed rock characteristics in boreholes with care, has found a layer of grayish brown mudstone contains diameter lmm quartz particles is rather stable in the area, can be a marker bed in coal seam prediction, on this account a formula to predict coal seam intersecting depth put forward and carried out coal seam prediction. The predicted results are in close proximity to actual intersecting depths. Thus considered the marker bed and prediction formula are reliable, can be the basis to guide following drilling operations.