一种用于水基压裂液伤害性评价的型煤制备方法

目前对于水基压裂液伤害性评价的方法主要是针对碎屑岩,没有专门针对煤的评价方法,就其原因在于难以制备实验用的煤心,也没有统一的制样方法。由于部分煤样裂缝发育、结构疏松难以制成柱塞样品最终导致伤害实验无法完成。因此,在大量实验的基础上我们采用四步制样法挑选出粒度为40目~70目的煤样,用30 MPa~40MPa的制样压力将煤样压制成型煤煤心,并利用热收缩管和导流垫块对煤心封装成形。通过该方法制备成的型煤煤心既克服了以往样品装卸困难,也保证了实验的重复性和数据的可考性,用该方法制备的型煤煤心已成功应用于水基压裂液对煤层伤害性评价。

Coal Core Make Meihod for Water-Based Fracturing Fluid Sensitivty Evaluation

At present, water -based fracturing fluid damage evaluation method is mainly used in the evaluation of elastic rock, there is no specific evaluation methods for coal. On the one hand, fracture development and loose coal samples were processed into cylindrical sample is very difficult. On the other hand , there is no uniform method of prep- aration of the artificial coal core. Because of the low permeability of the raw coal core, sensitivity evaluation experiments cant complete. Therefore, on the basis of a large number of experiments four steps sample preparation method were used to selected granularity for 40 ~ 70 coal samples, with 30 mpa -40 mpa pressure. Coal was made into coal core, and used as the heat shrinkable tube, guide block and packaging of coal core. The artificial coal core overcome the coal samples were difficult to install and remove, guaranteed the repeatability of the experiment and data reliability.