Influence of acid-rock reaction heat and heat transmission on wormholing in carbonate rock

Two-Stage Stimulation of Gas Carbonate Reservoirs with High Anhydrite Content: Experimental and Modeling Study

“…A fine-scale model was utilized to understand the impact of the two-stage treatment in stimulating anhydrite-rich carbonate minerals. The model is named “two-scale continuum”, where each element contains a solid and liquid fraction represented by the porosity. − The detailed mathematical description of the model is shown below. The finite-volume approach was implemented to solve the system of differential equations.…”

A reservoir-damage-free encapsulated acid dually controlled by hydrogen ion concentration and temperature

“…Aer adding one drop of methyl orange, the product from step (3) was titrated against hydrochloric acid with a concentration of about 0.25 mol L À1 until the light red solution turned colorless, with the volume of hydrochloric acid consumed recorded as V 2 . The SHA content of the EA was calculated with eqn (2).…”

“…With the development of the global oil and gas industry, oil and gas exploration and development extends from shallow layers to deep layers and ultra-deep layers and changes rapidly from medium-low temperatures to high and ultra-high temperatures. [1][2][3] High-temperature deep carbonate reservoir acid fracturing has introduced more stringent requirements, [4][5][6] a slower chemical reaction rate and excellent dissolution performance of acid systems, which means that the acid system still should have a certain dissolution ability above 135 C. [7][8][9] Existing acids for high temperatures with a slow chemical reaction rate include emulsied acids, 10,11 organic acids 12,13 and cross-linked acids. 14 Although these acid systems have a certain slow chemical reaction rate performance, they are in direct contact with the acid fracturing pipelines and therefore must be treated with corrosion inhibitor additives.…”

Development and application of a double action acidic emulsion for improved oil well performance: laboratory tests and field trials

“…Oil field development efficiency depends on well productivity over the entire life of the field. During the operation of production wells, the reservoir properties such as porosity and permeability in the vicinity of the well gradually deteriorate thus resulting in an increase of the skin factor [1,2]. Clogging of the formation near a production well is caused mainly by the formation of paraffin deposits.…”