Potassium amino polymer strong-inhibition anti-collapse drilling fluid for argillaceous siltstone stratum

Abstract

The invention relates to potassium amino polymer strong-inhibition anti-collapse drilling fluid for an argillaceous siltstone stratum. The potassium amino polymer strong-inhibition anti-collapse drilling fluid is prepared from the following components in percentage by weight: 1-1.5 percent of a potassium-amino polymer, 1-1.5 percent of an acid soluble fluid loss agent G310-SJS, 1.0-2.0 percent of sulfonated bitumen, 1-2 percent of a blocking agent, 0.3-0.6 percent of high-viscosity polyanionic cellulose PAC-HV, 0.3-0.6 percent of low-viscosity polyanionic cellulose PAC-LV, or A weighting agent optionally added according to actual requirements and of which a pH value is controlled to be 9-10 by using a basicity control agent, and the balance of water. The potassium-amino polymer is adsorbed on the surface of rock debris at multiple points, and positive point groups are introduced in a certain proportion, so that the adsorption capability is high, the rock debris can be effectively coated, thereby being easily cleared away by using solid control equipment, the low solid phase of the drilling fluid can be realized; in addition, the polymer is high in adsorbability so that a hydrate adsorption layer of the polymer is formed on a well wall to constrain a clay intercalation, thus achieving the effect of stabilizing the well wall.

Description

technical field [0001] The invention relates to a drilling fluid, in particular to a potassium ammonium polymer strong inhibition and anti-slump drilling fluid with strong inhibitory properties suitable for stabilizing the well wall of the mudstone section of a horizontal well in Changqing Oilfield. Background technique [0002] In oil and gas exploration and development, drilling costs account for 50%-80% of exploration and development costs. Research and application of advanced and applicable drilling technologies is the key to reducing drilling costs. Wellbore instability during drilling can easily lead to downhole complex situations and accidents such as wellbore collapse, diameter shrinkage, leakage, pipe sticking and reservoir pollution, which seriously restrict the development of oil and gas field exploration and development. Effective control of wellbore instability during drilling is the key to achieving high-quality, safe, high-efficiency and low-cost drilling thro...

AI Technical Summary

Problems solved by technology

However, with the development of new drilling fluid technology in recent years, its superiority has gradually lost, and some disadvantages have also been exposed: poor suppression ability of drilling fluid, rapid increase in density, rapid increase in submicron particles and solid phase content; short stability time , needs to be maintained at any time, the amount of glue supplemented is large; the anti-collapse effect is limited; the economic and technical indicators are poor, and the cost is high

This will directly lead to the extension of the drilling cycle and the increase of the cost

In particular, it may cause downhole complex situations such as wellbore instability

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