Recognition method for underground single ancient channel under condition of dense well pattern

Abstract

The invention discloses a recognition method for an underground single ancient channel under the condition of a dense well pattern. By adoption of an analogy method, field outcrop observation results are used for guiding recognition of the underground single ancient channel, and a model fitting geological thinking method is embodied. Through application of the recognition method in a Sulige gas field, quantitative description results are applied to three-dimensional geological modeling and serve as constraint conditions to enable the model consistency rate to be remarkably increased. According to the recognition method for the underground single ancient channel under the condition of the dense well pattern, aiming at morphological characteristics of the single ancient channel, dense well pattern drilling data are sufficiently utilized, tedious work of sedimentary micro-phase interpretation conducted on a single well is avoided, the phenomenon that the seismic datum longitudinal resolution ratio is not enough for determining is avoided, and the recognition method has the characteristic of being convenient to operate. According to application of the recognition method in the Sulige gas field, recognition accuracy of vertical sand bodies is improved to be less than 8 m from being 15-20 m, the original quantitative description results achieve quantification, the results are applied to three-dimensional geological modeling and serve as the constraint conditions to enable the model consistency rate to be increased by 10%, and the effect is obvious.

Description

[0001]

Technical field

[0002] The invention belongs to the field of geological analysis of oil and gas field reservoirs, and relates to a method for identifying an underground single paleo-channel under dense well pattern conditions.

[0003]

Background technique

[0004] Fluvial facies reservoirs have always been one of the key fields of oil and gas exploration and development in China. Vertical multi-stage single paleo-channel sand bodies are cut and superimposed one after another, and horizontally different single paleo-channel sand bodies in the same stage are spliced ​​with each other, forming a layered and complex structure. The fluvial facies river reservoirs have strong heterogeneity inside the reservoirs, which seriously restricts the further improvement of oil and gas recovery.

[0005] With the deepening of the development of fluvial oil and gas fields, oil and gas field stable production and enhanced oil recovery technologies have become the focus of domestic ...

Examples

Embodiment Construction

[0042] The present invention is described in further detail below in conjunction with accompanying drawing:

[0043] see Figure 1-3 , the underground single ancient channel identification method under the condition of dense well pattern of the present invention, comprises the following steps:

[0044] 1) Carry out high-precision stratigraphic division and correlation for the wells in the dense well pattern area, establish an isochronous stratigraphic correlation grid with accuracy reaching the single-layer level, and then take a single layer as the research object.

[0045] Dense well pattern area means that the well spacing is small enough to ensure that multiple wells can drill into the same single paleochannel, the smaller the well spacing, the more reliable the identification results; the single layer refers to the stratigraphic unit vertically composed of a single sedimentary period ;

[0046] 2) Aiming at the single layer, along the direction of the paleo-flow directi...

[0001]

Technical field

[0002] The invention belongs to the field of geological analysis of oil and gas field reservoirs, and relates to a method for identifying an underground single paleo-channel under dense well pattern conditions.

[0003]

Background technique

[0004] Fluvial facies reservoirs have always been one of the key fields of oil and gas exploration and development in China. Vertical multi-stage single paleo-channel sand bodies are cut and superimposed one after another, and horizontally different single paleo-channel sand bodies in the same stage are spliced ​​with each other, forming a layered and complex structure. The fluvial facies river reservoirs have strong heterogeneity inside the reservoirs, which seriously restricts the further improvement of oil and gas recovery.

[0005] With the deepening of the development of fluvial oil and gas fields, oil and gas field stable production and enhanced oil recovery technologies have become the focus of domestic ...

Examples

Embodiment Construction

[0042] The present invention is described in further detail below in conjunction with accompanying drawing:

[0043] see Figure 1-3 , the underground single ancient channel identification method under the condition of dense well pattern of the present invention, comprises the following steps:

[0044] 1) Carry out high-precision stratigraphic division and correlation for the wells in the dense well pattern area, establish an isochronous stratigraphic correlation grid with accuracy reaching the single-layer level, and then take a single layer as the research object.

[0045] Dense well pattern area means that the well spacing is small enough to ensure that multiple wells can drill into the same single paleochannel, the smaller the well spacing, the more reliable the identification results; the single layer refers to the stratigraphic unit vertically composed of a single sedimentary period ;

[0046] 2) Aiming at the single layer, along the direction of the paleo-flow directi...

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