ABSTRACT
Horizontal well drilling and completion technology to develop shallow reservoirs is a development mode actively recognized by major oil and gas fields at home and abroad at present, which is characterized by less investment, high output, and obvious economic benefits, but shallow horizontal wells have many difficulties in drilling and completion. In this paper, some reservoirs with buried depths between 340 m and 490 m are considered as an example. Because of shallow reservoir burial, a relatively large ratio of displacement to well depth, loose upper formation and high difficulty in deflection, the adjustment margin of wellbore trajectory control is very small, and there are some characteristics such as large wellbore friction during drilling and casing running. The technical difficulties and key technologies of shallow horizontal wells are summarized and analyzed, and the drilling fluid additives are optimized. Through the experimental study on the inhibition, drag reduction, lubricity, and rock carrying performance of the drilling fluid system for shallow horizontal wells, the drilling fluid system for shallow horizontal wells with small workover rigs is finally formed. It provides a new method for developing shallow reservoirs economically and effectively and enhancing oil recovery by using shallow horizontal well technology.
