Drilling And Production Problems In Hassi-Messaoud Field
Authors: Rederon C. , Brisac J. , Tartera M. , Repal S.N. , Labbe C. 
Published: December 2007

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This paper is to be presented at the 36th Annual Fall Meeting of the Society of Petroleum Engineers of AIME in Dallas October 8–11, 1961, and is considered the property of the Society of Petroleum Engineers. Permission to publish is hereby restricted to an abstract of not more than 300 words, with no illustrations, unless the paper is specifically released to the press by the Editor of JOURNAL OF PETROLEUM TECHNOLOGY or the Executive Secretary. Such abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in JOURNAL OF PETROLEUM TECHNOLOGY or SOCIETY OF PETROLEUM ENGINEERS JOURNAL is granted on request, providing proper credit is given that publication and the original presentation of the paper.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and considered for publication in one of the two SPE magazines with the paper.

Summary
The major problems of drilling and completion at Hassi Messaoud are :A strong flow of saturated salt water under a pressure of 580 kg per sq cm at a depth of about 2600 m.The presence of thick layers of salt and anhydrite above the producing horizon.A bed of heaving shale above the producing horizon.Loss of circulation resulting from the high mad density necessary to control the flow of salt water.
Several studies of drilling techniques have brought about improvements in the field. Improved mad composition and careful control of mad properties, among which may be mentioned the use of muds saturated with sodium or calcium chlorides, and centrifuging the mud, have reduced the time required for drilling and have facilitated setting casing.
Cements have been improved by the use of additives to prevent lost circulation and to reduce filtration. The use of cements prepared with saturated salt water has been studied.
The drilling of the producing horizon is conducted with the greatest care to prevent damage of the formation by the mud. About half of the wells are completed with oil base mud.

1. HISTORY OF THE FIELD
On January 16, 1956, an EMSCO Rig. JB-125O, belonging to the SOCIETE NATIONALE DE RECHERCHES ET d'EXPLOITATION DES PETROLES EN ALGERIE spudded in Md. 1, near the small water well of HASSI MESSAOUD. The first test of saturated sand demonstrated the importance of this discovery. On January 16, 1957, an Emsco Rig. 5.1400 of the COMPAGNIE FRANCAISE DU PETROLE (Algerie) rigged up several kilometers from Md. 1 and began drilling Om. 1, which found, at the end of May, the same productive horizon. The distance between these wells demonstrated the importance of the field, and the delineation of the productive area was pursued actively both by S.N. REPAL and C.F.P.(A). Actually, a considerable number of wells have been drilled, 104 wells having been finished by July 1, 1961, as can be seen in Fig. 1.
To transport the oil produced, a small line (6" diameter) was put in service in January 1958, between the field and the town of TOUGGOURT, whence the oil was carried by railway. This small line was replaced by a 24" line connecting HASSI MESSAOUD and the Mediterranean port of BOUGIE. The first tanker was loaded in this port on February 1958. Actual daily production at present is 32,000 cu. meters.

2. GEOLOGIC SECTION
The field is an immense, flat, anticlinal structure with gentle dip. Its limits are shown in Fig. 2. The surface area is about 1000 square kilometers. Fig. 3 presents a typical section of a well drilled at HASSI MESSAOUD:From 0 to 250 meters :Poorly consolidated coarse and fine sand.Partial, and sometimes complete, loss of circulation. Serious danger of sand caving, and of sticking of the drill pipe when it is necessary to come out of the hole following loss of circulation and a rapid lowering of the mud level in the hole.From 250 m. to 400 m. :Complete loss of circulation in the frequently fractured Senonian dolomites and dolomitic limestone.At 650 m. :Occurence of massive beds of salt in the Senonian.From 800 m. to 900 m. :Turonien limestone containing salt water of a concentration of 200 grammes per liter, under a pressure of 90 kg. per sq. cm. at a depth of 900 meters.From 1000 m. to 1400 m. :The Albien fresh water horizon with a pressure of 130 kg per sq. com at a depth of 100 m.