Development Evaluation and Optimization of Deep Shale Gas Reservoir with Horizontal Wells Based on Production Data

Table 1

Drilling technology system of Z2-H1.

Spud order	Drilling tools and techniques	Drilling fluid system	Drilling fluid density (g/cm^3)
1^st	PDC+tower/screw	Polymer	1.06-1.22
2^nd	PDC+screw	KCl-polymer/potassium-polysulfonate	1.17-1.42
3^rd	PDC+screw	Potassium-polysulfonate drilling fluid	1.97-2.11
4^th	PDC+rotary guidance+screw/routine	Oil-based drilling fluid	2.11-2.21
Spud order	Drilling tools and techniques	Drilling fluid system	Drilling fluid density (g/cm^3)