CONTROL FRACTURE IN SAND FORMATION USING SMART DRILLING FLUID THROUGHOUT EXPERIMENTAL APPROACH

Abstract

Control losses in geological formations consider as an important issue in drilling operation. Lost of
circulation can be one of the more serious problems that can arise during the drilling of an oil well or gas well. Loss
of drilling fluid can result in increased cost, loss of time, plugging of potentially productive zones, blowouts from
decreased hydrostatic pressure in formations other than the thief zone, excessive inflow of water, and excessive caving
of the formation. Lost circulation occurs through existing high-permeability zones such as highly fractured, vuggy, or
cavernous structures or induced fractures when the hydrostatic pressure of drilling fluid exceeds the breaking strength
of the formation. Carbonates are good examples of the former case. The following preventive measures can be used
however in other cases:1 a) set casing, b) maintain drilling fluid density, c) avoid excessive downhole pressures. d)
using high energy ball milling to oil based mud to observe the reduction in fluid loss as a result of the nano-additive,
the results were positive indicating up to 27.7% fluid loss reduction due to the ability of the suspended nano-material
to form compact impermeable mud cake as a result of its physical properties and increased surface area and interaction
potential. Core plugs with pre-determined properties were re-tested after the saturation test and showed encouraging
results with up to 15% permeability reduction and 8% porosity reduction.