Experimental evaluation on the damages of different drilling modes to tight sandstone reservoirs

Natural Gas Industry B

Liang Wang¹  Yingfeng Meng²  Limin Wang²  Gao Li²  Wuqiang Cai²  Xiaobing Zhang² 

[1] Gas Production Engineering Research Institute, PetroChina Southwest Oil & Gas Field Company, Guanghan, Sichuan 618300, China;State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China;

关键词: Drilling mode;    Air drilling;    Liquid-based underbalanced drilling;    Overbalanced drilling;    Tight sandstone;    Reservoir damage;    Permeability;    Experimental evaluation;   

DOI  :  10.1016/j.ngib.2017.08.008

来源: DOAJ

【 摘 要 】

The damages of different drilling modes to reservoirs are different in types and degrees. In this paper, the geologic characteristics and types of such damages were analyzed. Then, based on the relationship between reservoir pressure and bottom hole flowing pressure corresponding to different drilling modes, the experimental procedures on reservoir damages in three drilling modes (e.g. gas drilling, liquid-based underbalanced drilling and overbalanced drilling) were designed. Finally, damage simulation experiments were conducted on the tight sandstone reservoir cores of the Jurassic Ahe Fm in the Tarim Basin and Triassic Xujiahe Fm in the central Sichuan Basin. It is shown that the underbalanced drilling is beneficial to reservoir protection because of its less damage on reservoir permeability, but it is, to some extent, sensitive to the stress and the empirical formula of stress sensitivity coefficient is obtained; and that the overbalanced drilling has more reservoir damages due to the invasion of solid and liquid phases. After the water saturation of cores rises to the irreducible water saturation, the decline of gas logging permeability speeds up and the damage degree of water lock increases. It is concluded that the laboratory experiment results of reservoir damage are accordant with the reservoir damage characteristics in actual drilling conditions. Therefore, this method reflects accurately the reservoir damage characteristics and can be used as a new experimental evaluation method on reservoir damage in different drilling modes.

【 授权许可】

Unknown