Challenge and Successful Application for Scale Removal in Oil Field, Egypt: Field Study

Abstract

Abstract Water flooding is the hinge pin for Petrobel Oil Field. Water injection is supplied from shallow water supply wells. Compatibility tests, Petrographic Techniques and quantitative calculations of scale tendency using specific software had indicated probable deposition of calcium sulphate scale in the near-wellbore (Critical Matrix). Calcium sulphate scale, paraffin & was have been recognized to be a major operational problem. The bad consequences of scale formation& organic deposits comprised the contribution to flow restriction thus resulting in oil and gas production decrease. The nature of calcium sulphate scale is very hard and can't be dissolved with known dissolver. Sister companies that has similar problem were always going to the mechanical remover options which usually lead to further formation damage when invasion of formation rock by small particle sizes of the scale components. Extensive lab and field work was conducted to determine the suitable chemicals to dissolve calcium sulphate scale. The Production of Sidri formation which is currently contained 23 % of belayim land field OOIP (original oil in place) and currently contributes 27 % to the total oil production has been stopped dramatically in some wells. Sidri formation exhibits a high degree of permeability, heterogeneity and increase water injection was done in some areas that lead to increase the possibility of forming scale, most of scale in Belayim onshore is calcium sulphate. Precipitation of mixed organic/inorganic deposits (Calcium Sulfate Scale) resulted in decreasing the permeability in the critical matrix and perforation tunnels. Scale formed in the near-wellbore reduces oil production by blocking the narrow pore throats of the matrix itself This paper highlights Petrobel first application by using the new innovation product SCSR in Belayim land field (Sidri formation), its success and results based on extensive lab studies, SCSR was tested and applied through an effective treatment strategy proposed to remove the scale efficiently; the program was designed taking into consideration the nature of the scale. Furthermore the proposed treatments were conducted and placed using coiled tubing (CT).