Introduction

Onshore drilling mainly refers to discovery and development of hydrocarbons(oil and gas)on land. The term can also refer to drill in extereme land conditions such as ice covered field and desert. The process involves premilimary work, rigs selections, drilling in extreme conditions and well control.

The preliminary work includes finding a prospective location as recommended by geophysicists and geologists, land leasing agreement and approval from authorized body such as government or private land owner and rig personnel and infrastructure.

Selecting the appropriate rig is an important task which requires expertises and technicians. Rig needs to be placed in right position before starting the drilling operation. This section will include the history of drilling rigs, main components of modern drilling rigs and their basic operations, setting up the rigs and advance technologies of drilling rigs using in the world.

Drilling in challenging environments involves high temperature, high pressure and wells with high level of sour gas. Drilling in these conditions require new technologies to enhance safety and efficiency, minimise formation damage, and improve the production rate.

Well control is mostly about preventing incidents such as kicks, losses and blowout. Kick and blowout are mainly caused by reduction in fluid level via lost circulation, insufficient drilling fluid density, reduction of static pressure and failure to keep the hole full of fluid.