New Developed Acid Soluble Cement and Sodium Silicate Gel to Cure Lost Circulation Zones

Abstract

Abstract Moderate to severe loss of circulation problem encountered while drilling in Aramco field is a major economic burden that increases the total well construction cost dramatically in some cases. Complete or even partial control of the moderate to massive loss circulation problem may save thousands of dollars/per well and thus can make the drilling economics more economical. Saudi ARAMCO has developed a LCM formulation that can be used to cure lost circulation in the Middle East. The formulation consists of acid soluble cement and a sodium silicate gel that has a high potential to control moderate to severe loss circulation problem. Experimental data indicate that the control of loss of circulation using the silicate gel and soluble cement can be achieved as follows: 1) injection of the gel first into the fracture to penetrate the near fracture rock matrix, 2) pumping a small volume of spacer after the gel to delay the contact between the sodium silicate gel and the soluble cement, and finally 3) injection of soluble cement into the fracture to plug the fracture zone. Silicates have been used with cement to cure lost circulation and for water shut off treatment over the past 50 years. The major limitation of such technicue is rapid reaction and acid insoubility, Bauer et al. (2005). The objective of this paper is to introduce the use of acid soluble cement and sodium silicate gel as a possible solution to cure lost circulation zones in Saudi Arabia fields.