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Deep blockage removal and injection increase method for water injection well of medium-and-high-permeability sandstone reservoir

A technology for sandstone oil reservoirs and water injection wells, which is applied in the field of acidification and plugging removal, can solve the problems of no deep plugging, damage to water injection wells, and increase injection due to under attack, so as to achieve the effects of removing plugging damage, improving seepage capacity, and increasing injection effect.

Inactive Publication Date: 2015-01-21
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In fact, the blockage and damage of water injection wells are not only near the wellbore, but also very serious in the deep part. For example, the scaling of water injection wells in medium and high permeability sandstone reservoirs usually affects the zone with a radius of 10m. Sensitive damage usually occurs wherever the water injection affects. Bacterial damage is generally within 5m of the reservoir, and the existing technology mainly deals with short-radius blockages, and does not really achieve deep blockages to achieve undercutting. purpose of adding

Method used

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  • Deep blockage removal and injection increase method for water injection well of medium-and-high-permeability sandstone reservoir
  • Deep blockage removal and injection increase method for water injection well of medium-and-high-permeability sandstone reservoir

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Effect test

Embodiment 1

[0054] The long-term injection water quality of the Yong 3-141 well of Dongxin Oil Production Plant in Shengli Oilfield is poor, and the suspended matter content is 10-20 mg / L, which causes blockage near the wellbore and deep parts, resulting in under-injection, and the content of sensitive minerals in the reservoir is relatively low. high.

[0055] 1. Scheme design:

[0056] (1) During the acidizing injection enhancement, soaking and cleaning the scale near the blast hole is helpful to reduce the construction pressure. Secondly, the organic pollution of the reservoir injection water is removed to facilitate the removal of the scale and gray matter near the wellbore. The main acid solution is fluoboric acid and low-damage polyhydrogen retarded acid, and a stabilizer is added to ensure that various organic and inorganic scaling and salt deposition are reduced during the water injection process, so as to extend the validity period of the boost injection.

[0057] (2) The acidiz...

Embodiment 2

[0071] Well GDN15-502 of Gudao Oil Production Plant in Shengli Oilfield is a general polymer injection well. According to the previous polymer absorption profile data, the upper layer Ng53 and 54 do not absorb water and cannot be injected at 12MPa, so the upper layer needs to be acidified to remove plugging.

[0072] 1. Scheme design:

[0073] (1) In view of the fact that the injection time of the well is long, the formation has serious retention and clogging, and it is accompanied by the characteristics of clogging near the wellbore, firstly, pretreatment to remove oil pollution is carried out near the blast hole, using organic cleaning agent and active It is a compound product of agent, which is beneficial to remove organic blockage and improve the effect of cleaning oily dirt. In view of the fact that chlorine dioxide has a strong ability to oxidatively degrade polymers, oxidize and kill bacteria, remove bacteria, and dissolve sulfide deposits, the main acid uses chlorine d...

Embodiment 3

[0089] Dongxin Oil Production Plant Ying 12-136 Well of Shengli Oilfield, due to long-term reinjection of unqualified sewage and thick oil in the reservoir, caused serious blockage in the deep part.

[0090] 1. Scheme design:

[0091] (1) Implement multi-slug treatment process by optimizing the plugging solution formula: use organic plugging agent to remove organic pollutants in the early stage; the main acid first uses compound acid water injection well injection booster, this product has a strong ability to dissolve scale, The oil washing rate is as high as 95%; after that, tartaric acid is injected for matrix treatment. The purpose of stabilizing liquid is to stabilize calcium (magnesium), iron ions and other ions that are easy to scale, reduce water injection friction and surface tension, and prolong the validity period of water injection.

[0092] (2) The acidizing construction process is mainly divided into six slugs.

[0093] 2. Formula and quantity of working fluid ...

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Abstract

The invention provides a deep blockage removal and injection increase method for a water injection well of a medium-and-high-permeability sandstone reservoir. The method mainly solves the problems of oil pollution, deep blockage removal of a ground layer and the like of a sewage injection well, which can not be solved in the existing conventional acidification method. In the method, the slug type injection technology of "washing-clearing-blockage removing-stabilizing" is adopted; and the injection increase effect can be improved and the injection increase effective date can be prolonged. The method comprises the following steps: during construction, firstly, the well is backwashed at high displacement, and impurities near a well bore and a bore hole are washed; secondly, organic blockages near an oil layer are washed; then, organic and inorganic blockages in the areas near the well and the deep part of the oil layer are removed in the mode of multistage injection and multiple acid liquid systems, so that the seepage capability is improved; and finally, stabilizing treatment is adopted for prolonging the injection increase effective date. Through the adoption of the slug type injection technology, blockage damage is removed in batches, and substrate treatment, scale prevention treatment and scale inhibition treatment are performed so that the injection increase effect is improved, the injection increase effective date is prolonged and a better blockage removal effect is achieved.

Description

technical field [0001] The invention relates to the technical field of acidizing and plugging removal in oil field development, in particular to a method for removing plugging and increasing injection in the deep part of a water injection well of a medium-high permeability sandstone reservoir. Background technique [0002] Oilfield water injection is an important measure to maintain a certain level of formation pressure and improve oil recovery. Shengli Oilfield is mainly developed by water injection, and water injection development accounts for more than 80% of oilfields. Therefore, under-injection of water injection wells is becoming more and more serious. The decrease in permeability of sandstone oil layers is often caused by formation pollution and blockage: mainly mud pollution during drilling; formation clay particles moving in the production process to block formation pores; formation scaling caused by formation pressure and temperature changes and calcium, Blockage ...

Claims

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Application Information

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IPC IPC(8): E21B43/22E21B37/06C09K8/524
CPCE21B43/16C09K8/524C09K2208/12E21B37/06
Inventor 戴群李常友韦良霞渠慧敏罗杨王磊谭云贤陈勇
Owner CHINA PETROLEUM & CHEM CORP
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