Acid Fracturing Tight Gas Carbonates Reservoirs Using CO2 to Assist Stimulation Fluids: An Alternative to Less Water Consumption while Maintaining Productivity

2015 ◽  
Author(s):  
Mauricio Sanchez Bernal ◽  
Justin Tate ◽  
Muhammad Idris ◽  
J Eduardo Soriano ◽  
Alfredo Eduardo Lopez ◽  
...  
2015 ◽  
Author(s):  
Mauricio Sanchez ◽  
Justin Tate Abel ◽  
Muhammad Idris ◽  
Eduardo Soriano ◽  
Alfredo Lopez ◽  
...  

Abstract Conventional hydraulic fracture stimulation techniques have been widely used to enhance production from tight gas reservoirs. Since the initial use of this method to increase production rates, the industry has witnessed continued advancement in terms of fracturing theory, fluids, and techniques. The use of carbon dioxide (CO2) since the early 1960s has continued to be a significant part of these advances. CO2 has been used for many years as an energy source to aid fluid recovery of well stimulation fluids. This technology predominantly has been used to stimulate tight sandstone reservoirs. There are very limited applications for low permeable tight carbonate reservoirs because of complexities associated with the physical and mechanical properties of carbonate rocks and its interaction with fracturing fluid. Nevertheless, the advantages of using assisted CO2 stimulation fluids as the elimination of potential formation damage normally associated with fracturing fluids and very rapid cleanup are still present. This paper outlines one of the first acid fracturing jobs assisted with CO2 conducted on a tight gas well reservoir in Saudi Arabia. It describes in a simple manner the screening methodology and key parameters considered during selection of a well candidate and the design process, which was based on petrophysical, mechanical, and chemistry properties of the formation and the respective interaction with treatment fluids. Moreover, primary operational procedures and guidelines are discussed, highlighting a safety risk assessment point of view. Implementing this technique in a more generalized manner in the field can help save considerable operational time and costs. CO2 used to energized fracturing fluids can increase the productivity of the well while using less water and less acid than conventional acid fracturing, which is of primary importance in such a harsh environment, requiring less water consumption.


2021 ◽  
Vol 11 (4) ◽  
pp. 1761-1780
Author(s):  
Nianyin Li ◽  
Fei Chen ◽  
Jiajie Yu ◽  
Peihong Han ◽  
Jia Kang

AbstractHydraulic fracturing is an important technical means to improve the development effect of low-permeability oil and gas reservoirs. However, for low pressure, low-permeability, tight, and high-clay sandstone gas reservoirs, conventional propped fracturing can cause serious damage to the reservoir and restrict the fracturing effect. The pre-acid fracturing technology combines acid treatment technology with sand-fracturing technology. A pre-acid system that meets special performance requirements is injected before fracturing. The pre-acid reduces the formation fracture pressure and removes clay damage. During acid flowback, the fracturing fluid is promoted to break the gel, dissolve the fracturing fluid residue and polymer filter cake, clean the supporting cracks, and effectively improve the fracturing effect. This study analyzes the process principle and technical advantages of the pre-acid fracturing technology based on the laboratory evaluation of the fracturing damage mechanism of low-permeability tight gas reservoirs. To meet the performance requirements of low-permeability tight gas reservoirs and pre-acid fracturing technology, a set of polyhydrogen acid system with long-lasting slow reactivity, low damage, and low corrosion was developed and used as the pre-fracturing acid. The acid system is mainly composed of the main agent SA601 and the auxiliary agent SA701. Then, on the basis of laboratory experiments, this acid system is used as the fracturing pre-acid to evaluate the fracturing improvement effect. The results show that the fracturing fluid system can better dissolve the fracturing fluid filter cake and remove the fracturing fluid damage.


Petroleum ◽  
2015 ◽  
Vol 1 (3) ◽  
pp. 206-216 ◽  
Author(s):  
Nianyin Li ◽  
Jinxin Dai ◽  
Chao Liu ◽  
Pingli Liu ◽  
Yanming Zhang ◽  
...  

2006 ◽  
Author(s):  
Xianwen Li ◽  
Zhenfeng Zhao ◽  
Xu Ma ◽  
Xiaoduo Wang ◽  
Huanshun Zhou

2020 ◽  
Vol 0 (6) ◽  
pp. 13-19
Author(s):  
Guzel Gumerova ◽  
Georgiy Gulyuk ◽  
Dmitry Kucher ◽  
Anatoly Shuravilin ◽  
Elena Piven

Data of long-term researches (2015–2018) in southern forest-steppe zone of the Republic of Bashkortostan, is justified theoretically and experimentally the mode of irrigation of potatoes on leached chernozems of unsatisfactory, satisfactory and good ameliorative condition of irrigated lands. For the growing periods of potatoes with different heat and moisture supply, the number of watering, the timing of their implementation, irrigation and irrigation norms are established. On lands with unsatisfactory meliorative state the number of irrigation depending on weather conditions of potato vegetation period varied from 0 to 3 (1.5 on average) with average irrigation norm – 990 m3/ha. With satisfactory meliorative state of lands the number of irrigation on average increased from 0 to 4 (2.3 on average) with irrigation norm – 1305 m3/ha. On lands with good meliorative state the number of irrigation was the highest – from 1 to 5 (3 on average) with average irrigation irrigation norm is 1653 m3/ha. It was noted that in the dry periods of potato vegetation the greatest number of watering was carried out (3–5 watering), and in the wet periods (2017) watering was not carried out except for the area with a good reclamation state, where only one irrigation was carried out by the norm of 550 m3/ha. Water consumption of potato was studied in dynamics as a whole during the growing season and the months of the growing season depending on weather conditions of vegetation period and land reclamation condition of irrigated lands, as well as in the control (without irrigation). The lowest total water consumption was in the area without irrigation and averaged 226.8 mm. In irrigated areas, its values increased to 319-353.4 mm. The average daily water consumption varied from 2.12 to 3.3 mm. The highest rates of potato water consumption were observed in June and July, and the lowest – in May and August. In the total water consumption of potatoes on the site without irrigation, the largest share was occupied by atmospheric precipitation and in addition to them the arrival of moisture from the soil. Irrigation water was used in irrigated areas along with precipitation, the share of which was 30.2–46.1 %.


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