Multi-hydrogen acid composition and application thereof

Abstract

The invention provides a multi-hydrogen acid composition and application thereof. The multi-hydrogen acid composition consists of the following raw materials in percentage by weight: 6-8% of polyoxalic anhydride, 4-6% of villiaumite, 0.5-1% of high-temperature acidizing corrosion inhibitor, 1-2% of clay stabilizer, 5-10% of clean up additive, 1-2% of demulsifier, 2-5% of mutual solvent and the balance of water. The novel multi-hydrogen acid composition disclosed by the invention consists of polyoxalic anhydride, the villiaumite and the additive; the multi-hydrogen acid composition has strong dissolving capacity on quartz, clay and feldspar, and is capable of effectively improving permeability of a near-wellbore area reservoir and providing an important means for oil well production increase and water well injection increase; polyoxalic anhydride generates carbon dioxide and water after being degraded, so as to avoid environmental pollution.

Description

technical field [0001] The invention relates to a polyhydric acid composition and its application, and belongs to the technical field of petroleum exploitation. Background technique [0002] Almost all acid systems used in sandstone acidizing treatment contain HF or produce HF in the formation. Earth acid is the earliest and most common acid system used for sandstone reservoir acidification. However, due to the rapid reaction between HF and clay minerals, most of the acid solution is consumed near the wellbore, which eventually leads to the loss of acid solution in the reservoir. The penetration distance is short, and the effect of increasing production and injection is not ideal. At the same time, HF reacts with clay minerals, quartz, and feldspar in sandstone reservoirs to easily generate secondary precipitation and cause formation damage. In severe cases, the acidizing effect will be invalid. In response to this situation, in recent years, a polyhydric acid liquid syste...

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Problems solved by technology

However, due to their poor degradation performance, these phosphorus compounds are likely to cause eutrophic pollution of water after long-term use, promote the growth of bacteria and algae, increase the difficulty of water treatment, and remain in the natural environment for a long time, posing a serious threat to human health and the ecological environment.

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