Novel hydrogen sulfide scavenger for drilling liquid and preparing method of hydrogen sulfide scavenger

Abstract

The invention belongs to the technical field of removal of hydrogen sulfide gas of drilling shafts, and discloses a novel hydrogen sulfide scavenger for drilling liquid and a preparing method of of the hydrogen sulfide scavenger. Ferrous gluconate organic matter is adopted for the first time as a sulphur removal reagent for the drilling liquid, ferrous gluconate is a carbohydrate, the solubility is large, and dissolved ferrous ions quickly react with sulphur ions to generate a precipitate; the ferrous gluconate serves as the carbohydrate, and cannot pollute a drilling liquid system or oil andgas reservoirs; a chemical experiment evaluation is carried out between the ferrous gluconate and the hydrogen sulfide gas, the function law, the optimal function condition and the function mechanismof the ferrous gluconate and the hydrogen sulfide gas are determined, the harm concentration of the hydrogen sulfide gas intruding into a shaft can be greatly lowered, the corrosion of the hydrogen sulfide gas to a downhole drilling tool is reduced, and theoretical foundations and technical supports are provided for domestic exploitation of sulfur-containing oil and gas reservoirs.

Description

technical field [0001] The invention belongs to the technical field of removing hydrogen sulfide gas intruding into a wellbore in drilling engineering, and in particular relates to a novel hydrogen sulfide scavenger for drilling fluid and a preparation method thereof. Background technique [0002] At present, the existing technologies commonly used in the industry are as follows: my country has a large amount of sulfur-containing natural gas resources, mainly distributed in the Sichuan Basin, Bohai Bay, Ordos, Tarim and Junggar Basins. At present, the proven high H content 2 S natural gas accounts for 1 / 4 of the country's gas reservoir gas reserves, about 99 billion cubic meters; 2 / 3 of the gas fields in the Sichuan Basin contain H 2 S gas field; H in natural gas of Zhaolanzhuang sour gas reservoir in Huabei Oilfield 2 The S content is as high as 92%, which is one of the high sulfur gas reservoirs in the world. [0003] In recent years, with the increasing demand for gree...

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Problems solved by technology

[0008] 1) Sponge iron is a highly porous and non-magnetic synthetic iron oxide solid material, the main component is ferric oxide, which is almost insoluble; sulfur ions in the drilling fluid system will react with it to form FeS precipitation, which must diffuse to It takes a certain amount of time for the reaction process to penetrate the sponge iron surface and penetrate into its interior; when drilling high-sulfur oil and gas reservoirs, a large amount of H 2 S gas enters the wellbore, and the sponge iron has no time to react with it. Most of the hydrogen sulfide gas or dissolved sulfur ions return to the ground with the circulation of drilling fluid, posing a threat to the life safety of ground workers.

[0009] 2) Basic zinc carbonate and zinc compound substances have a certain solubility, which is better than sponge iron in removing hydrogen sulfide gas; but zinc substances are not easy to degrade, which seriously pollutes the formation environment; and zinc substances will change the water-based drilling fluid system The rheological properties of the drilling fluid will cause flocculation of the drilling fluid system. During the drilling process, if the rheological parameters of the drilling fluid are not well controlled, the rock-carrying ability of the drilling fluid system will decrease, and drilling accidents such as sand sinking and sticking will occur.

[0015] In recent years, in addition to the development of various inorganic compound sulfur removal reagents abroad, the efficiency of inorganic sulfur removal substances in removing hydrogen sulfide gas is not high, and the amount consumed in drilling operations is large, which will inevitably increase drilling costs; in addition, zinc-based drilling fluids The use of sulfur-removing substances will also cause drilling fluid flocculation, change the rheological properties of drilling fluid, and seriously cause the wellbore drilling fluid to be scrapped. At the same time, zinc-based drilling sulfur-removing substances must contain zinc ions, which will pollute the environment.

Therefore, foreign countries are gradually developing sulfur removal substances with high solubility. In addition to the development of zinc compound sulfur removal reagents in China, there is no other relatively complete drilling fluid sulfur removal technology, with few varieties and single functions.

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