Optimization of Matrix Acidizing With Fluids Diversion in Real-Time Using Distributed Temperature Sensing and Coiled Tubing

Abstract

Carbonate formations in southern Mexico are commonly stimulated using matrix acidizing treatments to increase well productivity by removing near-wellbore (NWB) damage. Such damage can be attributed to accumulation of paraffin and asphaltene deposits during the productive life of the well and, in other scenarios, to fluid invasion while performing workover activities. A high perforation length across the reservoir to increase production from this highly natural-fractured carbonate has been the completion option for several years. The use of diverters is a common practice in the Bellota-Jujo field when multiple intervals are open. However, the effectiveness of the diversion had not been evaluated in real-time. A distributed temperature sensing (DTS) option was deployed to measure temperature profiles along coiled tubing (CT) equipped with an internal fiber-optic cable and a modular bottomhole assembly (BHA) consisting of pressure, temperature, and depth correlation sensors. This option was selected to monitor the treatment and help make real-time decisions. This real-time fiber-optic (RTFO) integrated system used during the stimulation allowed identification of zones with higher and lower admission. Based on this information, decisions were made during the pumping schedule, modifying volumes and rates of diverting agents and stimulation fluids being pumped through the annular space between production tubing and CT, also pumping through CT using a fluidic oscillating tool optimizing the diversion process during different stages of the intervention. This system enabled the operator to correlate depth and continuously monitor the temperature changes across the producing zone of the well. The findings and results of the stimulation treatment with this technique used in the well, Bricol 2DL, are presented in addition to the thermal analysis of the DTS profiles. The use of the RTFO integrated system during a matrix stimulation treatment in a carbonate formation with high permeability contributed to successfully evaluating the effectiveness of the fluids and mechanical diversion resulting in a well productivity increase of 60%, thus keeping the well in production since the treatment was performed.

Swelling Behavior of Elastomers under Water, Oil, and Acid

“…In matrix acidizing, acid is injected into the well, penetrating the rock pores at pressures below fracture pressure. The acid dissolves the sediments and mud solids within the pores that are inhibiting the permeability of the rock, thereby enlarging the natural pores of the reservoir and stimulating the flow of hydrocarbons, but this acid does not react with the hydrocarbons [9,10].…”

An experimental study of acidizing operation performances on the wellbore productivity index enhancement

“…These techniques entail matrix acidizing and fracture acidizing; the former operates under the formation fracturing pressure by injecting reactive fluids (commonly hydrochloric acid) to dissolve and disperse the rock while creating highly conductive wormholes while the latter is performed above the formation fracturing pressure. One of the chief aims of this study is to enhance the reservoir permeability or remove the damages around the wellbore; that is to say that, acid treatment would make new channels among interconnected pores with higher permeability than the original permeability (Babaei and Sedighi 2017;Ghommem et al 2016;Medina et al 2015). Therefore, the primary purpose of any acidizing operations is to increase well production by removing damages which are caused by drilling operations or improving the physical conditions of the reservoir rock like porosity and permeability.…”

2 1/8-in. Intelligent Coiled Tubing System Improves Operational Efficiency

“…Among those, the most advanced ones employ a 1/8-in. insulated electrical conductor (Taggart et al 2010(Taggart et al , 2011Oberascher et al 2012;Livescu et al 2015) or an optical fiber (Aviles et al 2011;Garcia et al 2011;Ramondenc and Baez 2013;Ahmed et al 2014a,b;Gorgi et al 2014;Ramondenc et al 2014;Webb et al 2014;Medina et al 2015). The BHAs for both systems were designed to meet similar requirements.…”