Shedding light on the Horizontal Drilling Technique in Egypt, and the fruitful outcomes it can bring to the oil and gas industry, Steve Gauld, Business Development Manager of Baker Hughes Egypt exchanges more information about this trendy methodology
What is different about this technique?
Horizontal drilling is a natural extension of conventional directional drilling techniques. By taking a well to horizontal with reference to the formation dip, the production hole exposes significantly more reservoir. When done correctly, this increases both production and ultimate field recovery while simultaneously reducing the total number of wells required to drain a field.
What are the requirements of this type of drilling?
The key requirements are personnel competency and field proven technology. Horizontal wells are drilled using different drilling technologies ranging from steerable drilling motors, adjustable stabilizer systems right through to rotary steerable systems (RSS’s) and the more advanced Rotary Closed Loop Steerable (RCLS) systems. In most cases, formation evaluation logging while drilling (LWD) services are integrated with the drilling technologies. This information is used in real-time to land and then maintain the wellbores position within the most productive reservoir zones. In some cases, multiple zones are targeted for production from a single horizontal leg. Real-time LWD data is also used to monitor wellbore stability in order to identify and accurately diagnose the onset of instability which, if left unchecked, may result in wellbore collapse. It requires a team of competent personnel to minimize operational risk and maximize the value of the delivered well.
What are the pros and cons?
The pros are huge. Whole orders of magnitude increase in reservoir exposure from fewer wells delivers greater production at lower cost. In thin reservoirs, horizontal drilling may be the only way to exploit those reserves – thereby increasing the proven reserves of a province or company. By reducing the number of wells required to drain a field, safety is improved, environmental impact is reduced as well as overall field development cost and time to full production.
The cons are increased technical complexity and individual well cost. Higher cost equipment is normally employed on horizontal drilling projects and it requires competent personnel to successfully plan and execute each well on time and within budget. In geologically complex reservoirs, knowing precisely where to position each lateral leg is a challenge. This can be addressed by maximizing the information gathered from each well right from the very start of field development, feeding this into the geological model and employing expert reservoir navigation services to model and geo-steer wells to target for optimum payback. Wellbore stability studies should also be performed as early as possible in a field development to minimize risks associated with wellbore instability.
Is it applied here in Egypt?
Yes, officially commenced in the early 90’s however there maybe earlier horizontal wells drilled that we are not aware of.
If yes, how many wells are horizontally drilled? Where?
Averaging from 3-7 wells per year; in total more than 50 wells drilled in the Gulf of Suez, Sinai and Western Desert to date however new horizontal wells are being planned monthly.
What are the constraints facing the execution of horizontal drilling in Egypt?
Lack of knowledge/experience, increased expenditure to gain additional reservoir exposure, expense of loosing the horizontal section during the drilling phase due to wellbore or directional problem (TVD Uncertainty), pressure managements, or in the completion phase due to hole conditions.
Complicated subsurface structure, TVD Uncertainty, Thin bed reservoirs, depleted intervals, and dipping formations all require full understanding prior to drilling.