Testing of saudi shales for potential use in drilling fluids

Abstract

This paper presents the results of rheological, electrochemical nnd filtration analyses of Umm-er-Radhuma shales in Saudi Arabia. The analyses indicate that these shales could be used as a basic con-stituent of drilling fluids. A preliminary assessment of the raw material future requirements in the drilling operations in Saudi Arabia is made. The mineralogical and chemical analyses of Umm-er- Radhuma shales showed the presence of palygorskite in these sediments. These shales consisted of more than 95% clay size particles most of which were less than 0.2 ~m in size. The rheological behavior of palygorskite based fluids have been studied with and without the addition of chlorides and/or hydroxides ofNa, K, Ca and Mg. The changes in the rheolog-ical properties have been correlated with the mineralogy of the used clays. It is believed that Saudi Arabia will invest huge sums of money to increase its oil production capacity in order to meet the expected oil demand increase in the 90s. Drilling activities will consume a big share of the investment. It is found that, the use of Umm er Radhuma natural resources in the drilling of oil and water wells in Saudi Arabia will save millions of dollars that otherwise would have to be spent on importing the raw materials from elsewhere.