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A Selective Water Shutoff Technology for Low Porosity and Low Permeability Reservoirs

A selective and technological technology, applied in drilling compositions, wellbore/well components, chemical instruments and methods, etc., can solve the problem of poor water blocking effect, difficulty in stabilizing production of oil wells, and easy water channeling in oil layers and other problems, to achieve the effect of high water blocking rate, low oil blocking rate and strong water blocking ability.

Active Publication Date: 2019-02-15
PETROCHINA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Water channeling and water flooding are prone to occur in the oil layers of Naiman Oilfield, and the water flooding phenomenon of oil wells is serious. If it cannot be effectively treated, the oil displacement efficiency will continue to decline, and it will be difficult to stabilize the production of oil wells
In 2012, among the selected plugging process formulas selected for the research project of selective water plugging technology for fracturing wells in low-porosity and low-permeability reservoirs in Naiman Oilfield, since oil-soluble resins participate in plugging high-permeability formations with large pore throats, gel-type The effective components of the plugging agent are less, so the oil-soluble particle size is too large to enter the small pores to help participate in the plugging and other problems, so that the water plugging effect is not effective

Method used

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  • A Selective Water Shutoff Technology for Low Porosity and Low Permeability Reservoirs
  • A Selective Water Shutoff Technology for Low Porosity and Low Permeability Reservoirs
  • A Selective Water Shutoff Technology for Low Porosity and Low Permeability Reservoirs

Examples

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Effect test

Embodiment 1

[0028] This embodiment provides a kind of technology that Naiman Oilfield (the total salinity of formation water is between 5000-6000mg / L) Nai 1-48-46 well carries out selective water shutoff, and this technology comprises the following steps:

[0029] (1) Prepare 150 tons of selective water blocking agent

[0030] Prepare selective water blocking agent according to the following ratio:

[0031]

[0032] Mix the above raw materials and stir for a period of time to prepare a selective water shutoff agent; the selective water shutoff agent can be cured at 60°C for 35 hours to form a gel. After testing, its initial viscosity is less than 100mPa·s, and its gelling strength is greater than 50000mPa·s.

[0033] (2) Prepare 10 tons of sealing agent

[0034] Prepare the sealant according to the following proportions:

[0035]

[0036] The above-mentioned raw materials are mixed and stirred for a period of time to obtain a sealing agent; the sealing agent can be cured at 60° C...

Embodiment 2

[0044] This embodiment provides a kind of technology that Naiman Oilfield (the total salinity of formation water is between 5000-6000mg / L) Nai 1-48-20 well carries out selective water shutoff, and this technology comprises the following steps:

[0045] (1) Preparation of 129 tons of selective water blocking agent

[0046] Prepare selective water blocking agent according to the following ratio:

[0047]

[0048] Mix the above raw materials and stir for a period of time to prepare a selective water shutoff agent; the selective water shutoff agent can be cured at 60°C for 35 hours to form a gel. Its initial viscosity is less than 100mPa·s, and the gelling strength is greater than 50000mPa·s;

[0049] (2) Prepare 10 tons of sealing agent

[0050] Prepare the sealant according to the following proportions:

[0051]

[0052] The above-mentioned raw materials are mixed and stirred for a period of time to obtain a sealing agent; the sealing agent can be cured at 60° C. for 6 ...

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Abstract

The invention provides a selective water plugging technique for a low porosity and low permeability oil deposit. The technique comprises the following steps that a selective water plugging agent is poured into a formation for plugging water, and then a sealing agent is poured for sealing; raw materials for preparing the selective water plugging agent comprise cationic polyacrylamide, resorcinol, urotropin, oxalic acid and the balance water; the initial viscosity of the selective water plugging agent is lower than 100 mPa.s, and the gel strength is higher than 50000 mPa.s; and raw materials for preparing the sealing agent comprise acrylamide monomer, bisacrylamide, ferric thiocyanate, an initiator and the balance water. The problem that the phenomena such as water channeling and water logging are prone to occurring to oil layer in the region is well solved by applying the technique to the low porosity and low permeability oil deposit in Naiman oilfields, and the defect that other water plugging techniques cannot take part in sealing and plugging in low permeability formations is overcome, so that the recovery efficiency is improved, the yield is increased, and the economic benefits are increased.

Description

technical field [0001] The invention belongs to the technical field of oilfield development and drilling, and in particular relates to a selective water shutoff process for low-porosity and low-permeability oil reservoirs. Background technique [0002] Low-porosity and low-permeability reservoirs are generally those with low oil saturation, poor continuity, "start-up production pressure difference" phenomenon, and especially large seepage resistance and pressure consumption. The porosity is mainly distributed between 7-19%, and the permeability is mainly distributed at 86.91×10 -3 μm 2 the following. Water channeling and water flooding are prone to occur in the oil layers of Naiman Oilfield, and the water flooding phenomenon of oil wells is serious. If it cannot be effectively treated, the oil displacement efficiency will continue to decline, and it will be difficult to stabilize the production of oil wells. In 2012, among the selected plugging process formulas selected f...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): E21B33/13C09K8/508C09K8/512
CPCC09K8/5083C09K8/512C09K8/882C09K8/887E21B33/13
Inventor 李作臣曹斌王群贾晓明钟宝鲍晓晗毛雪吴瑞成静周莉莎
Owner PETROCHINA CO LTD