threaded buried pipeline for oil transportation

Date 11-15-2014 23:56

Very common in the upstream. HDPE poly pipe has replaced it because of cost, corrosion and fitting leak issues.
You can do poly for about 1/3 of steel. If you are planning on using old or used tubing be aware there are severe corrosion issues with bare magnetized pipe in certain soil conditions.

By Joey

Date 11-25-2014 04:57

I only encountered the use of threaded joints in galvanized piping (e.g. for fire water systems). Then, there is also some limit on minimum wall thk (pipe sch 80).
Normally, there is this Design and Engineering Practice that the owner-user is providing to all their contractors. You may consider asking for it.

Threaded or Screwed Joints

In principle, threaded or screwed piping is commonly used in low-cost, noncritical applications such as domestic water, fire protection, and industrial cooling water systems. Installation productivity is moderately high, and specialized installation skill requirements are not extensive. Leakage integrity is good for low-pressure, low-temperature
installations where vibration is not encountered. Rapid temperature changes may lead to leaks due to differential thermal expansion between the pipe and fittings.
Vibration can result in fatigue failures of screwed pipe joints due to the high stress intensification effects caused by the sharp notches at the base of the threads. Screwed
fittings are normally made of cast gray or malleable iron, cast brass or bronze, or forged alloy and carbon steel. Screwed construction is commonly used with galvanized
pipe and fittings for domestic water and drainage applications. While certain types of screwed fittings are available in up to NPS 12 (DN300), economic considerations
normally limit industrial applications to NPS 3 (DN 80). Screwed piping systems are useful where disassembly and reassembly are necessary to accommodate
maintenance needs or process changes. Threaded or screwed joints must be used within the limitations imposed by the rules and requirements of the applicable code.

By dbigkahunna (****)

Date 11-26-2014 17:12

In onshore upstream there is NO design or engineering practice. These systems seldom exceed 50 psi as the limiting factor is the water knockout or heater treater in the battery. API 12R1 shows a typical battery lay-out and most battery fittings are either threaded or Victaulic connections.
It was common before the NORM days for the operator to use scrap tubing for flowlines. This is where you hear about the welding rod sticking to 2 inch pipe and wild arc blow.
But today poly is laid from the wellhead to the battery header. If it is tertiary recovery, fiberglass may be used due to its corrosion resistance to the carbolic acid which is formed with CO2 and water. And fiberglass is the primary piping material from the battery to the injection well. Where the fiberglass transitions with corrosion resistant pipe such as stainless steel.
When you get into upstream, engineering and codes tend to go out the window. Fired heater treater holding 20 PSI without a NB#. And yes, they blow them up as happened in Odessa yesterday.
It is better today than 10 years ago but I can show you things they do today that will scare you, but there is noting that prevents the operator from doing it. Risk and consequence are low and regulators non-existent. And when regulators are there, they are very industry friendly. You keep the mess on the production and no one gets killed or seriously hurt then carry on.