Organophilic Clay-Free Drilling Fluid Enriches Tight-Reservoir Productivity

_

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 36051, “Enriching Productivity by Using Organophilic Clay-Free Reservoir Drilling-Fluid Technology on Tight Reservoirs,” by Mohamed H. Madad, Ahmed A. Abulnasr, and Mohamed Elmashad, Halliburton. The paper has not been peer-reviewed.

_

This paper presents the methodology for developing drill-in organophilic clay-free invertemulsion- fluid technology that enhances well production through fundamental geological studies and fluid testing.

Maximizing asset value is a major drilling challenge in supertight fields. This paper presents the methodology for developing drill-in organophilic clay-free (DIOCF) invert-emulsion-fluid (IEF) technology that enhances well production through fundamental geological studies and fluid testing.

Using a customized DIOCF system resulted in successful drilling and completion of substantially tight-permeability reservoirs.

Lithology

The target reservoir is a significant Ordovician-age geological formation. It is characterized by tight sandstone formations primarily composed of mature quartz arenites with a high silica content. The reservoir consists predominantly of quartz arenites, indicating a mature sandstone with extensive quartz overgrowth. The presence of natural fractures, ranging from partially open to closed, has been observed, which can affect fluid flow and reservoir performance. These fracture systems often are oriented parallel to the regional tectonic stress field and are mineralized with quartz and minor calcite.

Geomechanical modeling of the quartzite reservoir revealed that it is a mechanically competent formation. The formation’s high stiffness supports its ability to resist wellbore collapse; however, its natural fracture system renders it susceptible to severe mud losses if not effectively managed.