Breakthrough Stimulation Method: Dilation Cyclic Extended Breakdown to Enhance Well Injection Performance and Stimulation Cost Efficiency in South Sumatra -Indonesia

Abstract

Water injection is an essential part of brown oilfield development plan both of pressure maintenance or water production management. The high cost and often tight economic margins associated with injection wells capacity require that the chosen stimulation technique not only provides an effective result to maximize injection well capacity but also carries an acceptable risk in term of the project cost and safety. Many well known techniques, such as fracturing and matrix acidizing have been developed over the years to achieve this result and are common in most water injection well operations. The objective of this paper is to show a new approach of stimulation technique can be maximized both of injection capacity and cut operational cost Dilation Cyclic Breakdown is a breakthrough stimulation technique through hydraulic treatment by injected high volume of formation water into the reservoir below tensile stress and above shear stress. The primary design that have led to these technique include the following steps : Certain criteria were used for pilot well such as hall plot and single well of nodal analysis. Operation can be performed by rigless operation and no chemical additive needed, equipment selection is approached by 3D fracture simulator both surface pressure and injection rate correlated to mechanical earth model syntethic. Pumping schedule and the number of cycle is optimized by pressure calibration analysis during Breakdown test, Step Rate Test and decline pressure analysis. It was critical that Step Rate Test and decline pressure analysis procedure be performed to determine fracture gradient as upper bound pressure and shear gradient as lower bound pressure. Various procedures were used in handling data recorded. Injection and pressure data from each well were plotted to observe the trend in the rate - pressure relationship. Nine injection wells were stimulated during 2020 - 2021. It has been an attractive result both of cut operational cost and increase injection capabilities. The operational cost per well can be reduced to $ 46,000 or 72% cheaper than matrix acidizing stimulation and the total incremental injection rate reach to 14,907 Bwipd or 1,656.3 Bwipd per well. A half of those injection wells were previously stimulated by matrix acidzing method but has not yet improved significantly. In addition, this method is also applied for two oil producer wells in sandstone reservoir as a pilot test. The increasing of Productivity Index greater 6.5 - 8x than initial as a result and has still been observed. Furthermore, this paper should be beneficial to all engineers currently working in brown and marginal Oil Field with tight economic margins to increase the production.