螺桿泵井桿管偏磨預(yù)防研究*

王亞娟

(西安城市建設(shè)職業(yè)學(xué)院，陜西 西安 710114)

螺桿泵井桿管偏磨預(yù)防研究*

王亞娟

(西安城市建設(shè)職業(yè)學(xué)院，陜西 西安 710114)

隨著地面驅(qū)動(dòng)螺桿泵在油田逐步推廣存在桿管偏磨現(xiàn)象，嚴(yán)重制約了地面驅(qū)動(dòng)螺桿泵的發(fā)展。對(duì)抽油桿工作時(shí)的受力進(jìn)行了分析，考慮井液阻尼作用，采用Ansys中的Damped法對(duì)抽油桿進(jìn)行了模態(tài)分析，通過(guò)仿真分析發(fā)現(xiàn)，桿管偏磨主要發(fā)生在抽油桿中下部，在抽油桿中部最嚴(yán)重，依此提出了上疏下密扶正器安裝法。提出通過(guò)控制轉(zhuǎn)速、沉沒(méi)度、井液密度和含蠟量，采用固體潤(rùn)滑劑減磨扶正器等措施來(lái)預(yù)防桿管偏磨。

螺桿泵；桿管；偏磨；仿真；預(yù)防

Abstract: As the surfac-driven screw pumps are gradually applied in oil fields, the phenomenon of rod-tubing partial abrasion has seriously restricted the development of surface-driven screw pumps. Aimed at rod-tubing partial abrasion, considering the fluid damping effect, the working stress of the sucker rod is analyzed, the Ansys damped method is used to analyze the modal of the sucker rod, it is found that the partial abrasion mainly occurs in the middle and bottom of the sucker rod, the partial abrasion in the middle of the sucker rod is the most serious by simulation, the method of sparse-up and dense-down installing centralizers is presented. Aimed at the factors affecting rod-tubing partial abrasion, the measures that are used to prevent the rod-tubing partial abrasion by controlling spin velocity, controlling submergence depth, controlling the well fluid density and wax content and using solid lubricant antifriction centralizers is presented.

Key words: screw pump; rod-tubing; partial abrasion; simulation; prevention

0 引 言

螺桿泵具有低能耗，效率高，占地面積小，使用維護(hù)方便，適合開(kāi)采高粘度，高含沙和高含氣原油等優(yōu)點(diǎn)[1]，在油田上越來(lái)越廣泛應(yīng)用。桿管偏磨，嚴(yán)重制約了其發(fā)展。桿管偏磨是檢泵的主要原因，嚴(yán)重制約著螺桿泵的發(fā)展，所以對(duì)螺桿泵井進(jìn)行桿管偏磨預(yù)防研究顯得尤為重要。

1 桿管偏磨原因分析

抽油桿工作時(shí)受力十分復(fù)雜，主要受周向扭矩和豎直方向的軸向力作用，二力作用導(dǎo)致桿管偏磨的發(fā)生。以下主要對(duì)抽油桿所受扭矩和軸向力進(jìn)行分析。

1.1 抽油桿負(fù)載扭矩分析

螺桿泵采油中，抽油桿所受扭矩主要有5種，可表示為[2]：

M=M1+M2+M3+M4+M5

(1)

(2)

M2=91.3σ0-n0.45+47+K0σfnR

(3)

(4)

(5)

(6)

式中：M為抽油桿負(fù)載扭矩，N·m；M1為螺桿的有功扭矩，N·m；M2為襯套與螺桿泵間的摩擦扭矩，N·m；M3為抽油桿與井液的摩擦扭矩，N·m；M4為抽油桿與油管的摩擦扭矩，N·m；M5為抽油桿的慣性扭矩，N·m；……